Orientador: Luis Guillermo Bahamondes / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas / Made available in DSpace on 2018-11-07T16:42:18Z (GMT). No. of bitstreams: 1 Juliato_CassiaRaquelTeatin_D.pdf: 2310620 bytes, checksum: fd8518fdd702439cfec0703cbfc61af7 (MD5) Previous issue date: 2006 / Resumo: O objetivo deste estudo foi avaliar a densidade mineral óssea (DMO) em usuárias de dois tipos de contraceptivos injetáveis combinados (CIC) mensais e comparar com controles. SUJEITOS E MÉTODOS: Estudo de corte transversal com 97 mulheres de 20 a 45 anos, usuárias de CIC com 25mg de acetato de medroxiprogesterona e 5mg de cipionato de estradiol (AMP/CypE2, Cyclofemina) por 12 a 82 meses (n=64) ou 50mg de enantato de norestisterona e 5mg de valerato de estradiol (NET-EN/ValE2, Mesigyna) por 12 a 60 meses (n=33), pareadas por idade (± 1ano) e índice de massa corpórea (IMC, kg/m2) (± 1) com usuárias de DIU TCu 380A como grupo de controle. A DMO foi avaliada nas regiões distal e ultradistal do rádio, no braço não dominante, utilizando a técnica de absorciometria óssea, com feixe duplo de raios-X (DXA). RESULTADOS: A DMO no midshaft da ulna foi de 0,457 ± 0,007 nas usuárias de Cyclofemina® e 0,465 ± 0,007 nos controles. Nas usuárias de Mesigyna® a DMO foi 0,463 ± 0,008 e 0,458 ± 0,009 nos controles. No rádio distal, a DMO foi 0,399 ± 0,011 e 0,401 ± 0,010 nas usuárias de Cyclofemina® e controles, e 0,400 ± 0,009 e 0,388 ± 0,10 nas usuárias de Mesigyna® e controles, respectivamente. Não houve diferença na DMO entre as usuárias de CIC e o grupo de controle. Não houve diferença entre as usuárias dos dois tipos de CIC e também não houve diferença entre as usuárias de CIC com relação ao tempo de uso menor ou igual e a partir de três anos. CONCLUSÕES: Mulheres com idade entre 20 e 45 anos, usuárias de CIC com AMP/CypE2 ou NET-EN/ValE2, apresentaram DMO similar entre os dois tipos de CIC e controles (usuárias do DIU TCu 380A), quando pareadas por idade e IMC / Abstract: BACKGROUND: The objective of this study was to compare bone mineral density (BMD) between users of two kinds of once-a-month combined injectable contraceptives (CIC) and controls. SUBJECTS AND METHODS: This crosssectional study included 97 women of 20 to 45 years of age, using CIC containing either 25 mg of medroxyprogesterone acetate and 5 mg of estradiol cypionate (MPA/E2Cyp, Cyclofemina) (for 12 to 82 months) or 50 mg of norethindrone enanthate and 5mg of estradiol valerate (NET-EN/E2Val, Mesigyna) (for 12 to 60 months) matched by age (± 1 year) and body mass index (BMI, kg/m2) (± 1) with users of the TCu 380A intrauterine device as controls. BMD was evaluated at the midshaft of the ulna and at the distal section of the radius of the nondominant forearm using double X-ray absorptiometry. RESULTS: The BMD at the midshaft of the ulna was 0.457 ± 0.007 and 0.465 ± 0.007 in the MPA/oE2Cyp group and controls, respectively, and 0.463 ± 0.008 and 0.458 ± 0.009 in the NET-EN/oE2Val group and controls, respectively. At the distal radius, the BMD was 0.399 ± 0.011 and 0.401 ± 0.010 in users of MPA/oE2Cyp and controls, respectively and 0.400 ± 0.009 and 0.388 ± 0.010 in users of NET-EN/oE2Val and controls, respectively. There were no differences in BMD between users of either CIC and non-users at either section of the forearm studied. There were also no differences in BMD between users of the two CIC at either section of the forearm. CONCLUSIONS: Women aged 20 to 45 years old, currently using one of these two kinds of CIC, presented similar BMD to controls paired by age and BMI (kg/m2) and similar between both CIC / Doutorado / Tocoginecologia / Doutor em Tocoginecologia

As propriedades anti-inflamatórias e imunossupressoras dos glicocorticoides (GC) justificam o uso destes esteroides em diversas condições clínicas, apesar dos seus importantes efeitos adversos. A osteoporose induzida por glicocorticoide (OIG) é considerada a causa mais importante de osteoporose secundária. Trata-se de uma doença multifatorial que envolve alterações sistêmicas, teciduais e da sinalização das células ósseas. Além disso, o hipercortisolismo também se associa à obesidade, redistribuição de gordura, resistência insulínica e diabetes mellitus. Curiosamente, nestes distúrbios metabólicos em que a massa óssea está preservada, há maior fragilidade óssea. Nos últimos anos, diversas evidências mostram complexa interação entre o metabolismo mineral e o energético, em particular entre o tecido adiposo e ósseo. Neste cenário, a doença de Cushing (DC) é um modelo clínico conveniente para avaliar diversos mecanismos envolvidos no complexo processo de desenvolvimento de osteoporose. O objetivo deste trabalho foi avaliar, em um estudo basal e em um estudo prospectivo, diversos aspectos da interação entre o metabolismo mineral e energético em mulheres com DC e o seu possível impacto sobre a massa óssea, bem como a associação entre a massa óssea e os diversos tipos de tecido adiposo. No estudo basal, avaliamos três grupos de indivíduos, pareados por sexo e idade: grupo controle (C; n=27), grupo obeso (O; n=16) e grupo doença de Cushing (DC; n=16). No estudo prospectivo, avaliamos o grupo DC em três momentos: pré-operatório (Pré-op; n=11), 6º mês pós-operatório (6º mês PO; n=10) e 12º mês pósoperatório (12º mês PO; n= 10). No estudo basal, os grupos O e DC diferiram em relação ao C quanto ao peso e IMC (p<0,05). O grupo DC apresentou valores significativamente maiores de glicemia, insulinemia, hemoglobina glicosilada (HbA1c), HOMA-IR e leptina em relação aos grupos C e O (p<0,05). Adicionalmente, o grupo DC mostrou níveis baixos de osteocalcina em relação aos grupos C e O (p<0,05) e também de PTH, 25-OH vitamina D (25(OH)D) e adiponectina em relação ao grupo C (p<0,05). Não houve diferença entre os grupos em relação às dosagens de IGF-I e preadipocyte factor 1 (Pref-1). O grupo DC apresentou menor massa óssea em coluna lombar em relação aos grupos C e O (p<0,05) e menor massa óssea em corpo total quando comparado ao grupo O (p<0,05). O Trabecular bone score (TBS) foi capaz de evidenciar prejuízo na qualidade óssea nos grupos O e DC, mostrando comprometimento maior no grupo DC (p<0,05). A adiposidade de medula óssea (AMO) de L3 foi significativamente maior no grupo DC em relação aos grupos C e O (p<0,05). O grupo DC apresentou maior teor de tecido adiposo subcutâneo (SAT), visceral (VAT), relação VAT/SAT e de lipídeos intra-hepáticos (IHL) em relação ao grupo C (p<0,05). Adicionalmente, o grupo DC apresentou maior teor de VAT em relação ao grupo O (p<0,05). A osteocalcina se correlacionou de maneira positiva com TBS (r=0,5, p<0,0001) e negativa com HOMA-IR (r=-0,4, p<0,01) e AMO de L3 (r=-0,4, p<0,01). O TBS apresentou correlação negativa com HOMA-IR (r=-0,6, p<0,0001) e AMO de L3 (r=-0,5, p<0,001). A AMO de L3 se correlacionou positivamente com IMC (r=0,4, p<0,01), HOMA-IR (r=0,3, p<0,05), leptina (r=0,3, p<0,05), relação VAT/SAT (r=0,6, p<0,0001) e IHL (r=0,5, p<0,05). No estudo prospectivo, houve redução do peso e IMC e dos níveis de glicemia, insulinemia, HOMA-IR, hemoglobina glicada e leptina (p<0,05). Adicionalmente, houve aumento dos níveis de 25(OH)D, osteocalcina e deoxipiridinolina (p<0,05). Não houve diferenças significativas entre os níveis de Pref-1 e adiponectina. O TBS manteve-se estável e não houve aparecimento de novas fraturas pelo vertebral fracture assessment (VFA). Na composição corporal por dual-energy X-ray absorptiometry (DXA), houve redução da massa gorda total e melhora no índice de massa magra apendicular pelo Foundation for the National Institutes of Health (FNIH) (p<0,05). A AMO de L3 reduziu significativamente no 6º mês PO, mantendo-se estável no 12º mês PO (p<0,05). Houve redução significativa do VAT, relação VAT/SAT e IHL no seguimento prospectivo (p<0,05). O presente estudo reafirma dados anteriores que mostram que o hipercortisolismo endógeno exerce profundo efeito negativo sobre o esqueleto, em particular sobre o osso trabecular. Além disto, é o primeiro estudo a mostrar que existe correlação negativa entre o TBS com HOMA-IR e AMO; é possível que as alterações do metabolismo energético sejam, pelo menos em parte, responsáveis pelo maior risco de fratura na DC. / The anti-inflammatory and immunosuppressive properties of glucocorticoids (GC) justify the use of these steroids in various clinical conditions, despite its significant adverse effects. Osteoporosis induced by glucocorticoids (OIG) is considered the most important cause of secondary osteoporosis. It is a multifactorial disease involving systemic, tissue and bone cell signaling changes. Furthermore, hypercortisolism is also associated with obesity, redistribution of fat, insulin resistance and diabetes mellitus. Interestingly, these metabolic disorders in which bone mass is preserved, there is increased bone fragility. In recent years, evidence shows various complex interaction between the mineral and energy metabolism, in particular between adipose tissue and bone. In this scenario, Cushing\'s disease (CD) is a desirable clinical model to evaluate various mechanisms involved in the complex process of developing osteoporosis. The objective of this study was to evaluate, in a baseline study and a prospective study, various aspects of the interaction between the mineral and energy metabolism in women with DC and their possible impact on bone mass, as well as the association between bone mass and different types of adipose tissue. In the baseline study, we evaluated three groups of individuals, matched by sex and age: control group (C, n = 27), obese (O; n = 16) and Cushing\'s disease group (CD, n = 16). In the prospective study, we evaluated the CD group at three time points: preoperative (Pre-op; n = 11), 6 months postoperative (6th month PO; n = 10) and 12 months postoperatively (12th month PO; n = 10). In the baseline study, the O and CD groups differed in relation to C as the weight and BMI (p <0.05). The CD group showed significantly higher blood glucose, insulin, glycosylated hemoglobin (HbA1c), HOMA-IR and leptin in relation to the C and O groups (p <0.05). Additionally, the CD group showed lower levels of osteocalcin in relation to the C and O groups (p <0.05) as well as PTH, 25-OH vitamin D (25 (OH) D), and adiponectin in relation to the C group (P <0.05). There was no difference between the groups regarding dosages of IGF-I and preadipocyte factor 1 (Pref-1). The CD group had lower bone mass in the lumbar spine in relation to the C and O groups (p <0.05) and lower bone mass in the total body when compared to the O group (P <0.05). The Trabecular bone score (TBS) was able to show impaired bone quality in groups O and CD, showing greater involvement in CD group (p <0.05). Bone marrow adiposity (BMA) in L3 was significantly higher in the CD group compared to the C and O groups (p <0.05). The CD group showed increased subcutaneous fat content (SAT), visceral (VAT), VAT/SAT ratio and intrahepatic lipid (IHL) in relation to the C group (p<0.05). Additionally, the CD group had a higher content of VAT in relation to the O group (p<0.05). Osteocalcin correlated positively with TBS (r = 0.5, p <0.0001) and negatively with HOMA-IR (r = -0.4, p <0.01) and AMO of L3 (r = - 0.4, p <0.01). The TBS was negatively correlated with HOMA-IR index (r = -0.6, p <0.0001) and AMO of L3 (r = - 0.5, p <0.001). The AMO of L3 positively correlated with BMI (r = 0.4, p <0.01), HOMA-IR (r = 0.3, p <0.05), leptin (r = 0.3, p < 0.05), VAT/SAT ratio (r = 0.6, p <0.0001) and IHL (r = 0.5, p <0.05). In the prospective study, there was a reduction in weight and BMI and blood glucose, insulin, HOMA-IR, glycated hemoglobin and leptin (p <0.05). Additionally, there was increased levels of 25(OH)D, osteocalcin and deoxypyridinoline (p <0.05). There were no significant differences between the levels of adiponectin and Pref-1. The TBS was stable and there was no occurance of new fractures by vertebral fracture assessment (VFA). In body composition by dual-energy X-ray absorptiometry (DXA), threre was a reduction of total fat mass and improvement in apendicular lean body mass index by Foundation for the National Institutes of Health (FNIH) (p <0.05). The BMA of L3 significantly reduced in the 6th month PO, remaining stable on the 12th month PO (p <0.05). There was a significant reduction of VAT, VAT/SAT ratio and IHL in the prospective follow-up (p <0.05). This study confirms previous data showing that endogenous hypercortisolism has a profound negative effect on the skeleton, in particular on trabecular bone. Moreover, it is the first study to show that there is a negative correlation between TBS with HOMA-IR and BMA; it is possible that changes in energy metabolism are at least partly responsible for the increased risk of fracture in DC.

O objetivo deste trabalho foi avaliar a associação de calcificação da aorta abdominal (CAA) com marcadores do metabolismo ósseo: densidade mineral óssea (DMO), dados laboratoriais (cálcio, fósforo, 25OH-vitamina D, PTH) e clínicos em uma população brasileira de idosos. Este foi um estudo de corte transversal onde foram incluídos 815 indivíduos com idade igual ou superior a 65 anos. Os dados demográficos e de estilo de vida, bem como os parâmetros clínicos que identificam os fatores de risco para osteoporose e calcificação vascular foram obtidos por um questionário padronizado. Densidade mineral óssea (DMO) e parâmetros laboratoriais foram avaliados em todos os indivíduos. Foram realizadas radiografias de coluna lombar para a análise de calcificação da aorta abdominal nos segmentos correspondentes às vértebras L1 a L4. Para cada segmento lombar foi dada uma pontuação de 0-3 para as paredes anterior e posterior, com um escore máximo de 24 pontos (Kaupilla et al., 1997). Resultados: 63,2% dos idosos apresentavam algum grau de CAA, com um escore médio de 4,68 5,88. Analisando as variáveis contínuas observamos que o escore de CAA foi correlacionado diretamente à idade, fósforo sérico, LDL-colesterol (LDL-C), triglicérides e inversamente ao índice de massa corpórea (IMC), DMO do colo do fêmur e DMO do fêmur total (p<0,05). Em relação às variáveis binárias o escore de CAA foi associado à história de fraturas prévias por fragilidade, baixa atividade física, quedas no último ano, tabagismo atual e hipertensão arterial (p<0,05). A análise de regressão linear múltipla demonstrou que o escore de CAA foi diretamente relacionado à idade (p<0,001), tabagismo atual (p<0,001), hipertensão arterial (p=0,002), LDL-C (p=0,05), triglicérides (p=0,002), fósforo sérico (p=0,005) e inversamente associado à DMO de fêmur total (p<0,001). Um aumento no escore de CAA foi observado com a elevação dos níveis séricos de fósforo [ 2,4mg/dL: escore de CAA = 1,9 (DP: 3,9); 2,5-3,5mg/dL: escore de CAA = 4,5 (DP: 5,6) e > 3,5mg/dL : escore de CAA = 5,3 (SD: 6,3) p=0,003]. Este estudo demonstrou que, além dos fatores de risco clássicos para doença cardiovascular (HAS, tabagismo e lípides), o fósforo sérico e a DMO do fêmur total foram fatores de risco adicionais ao complexo processo de calcificação vascular em idosos da comunidade / The aim of this study was to analyze abdominal aortic calcification (AAC) and its possible association with bone mineral density (BMD) as well as the clinical and laboratory data. This was a cross-sectional study conducted between 2005 to 2007, with a population-based sample of older men and women living in Brazil. Eight hundred and fifteen subjects 65 years old were studied. The risk factors for osteoporosis and cardiovascular disease, demographic data and lifestyle characteristics were collected using a standardized questionnaire. BMD was measured by DXA. Kauppilas method was used to quantify the AAC score (AACS) by spine X-rays. Laboratory analyses were also performed. AAC was observed in 63.2% of subjects with a mean AACS of 4.68 (5.88). AACS was directly correlated with age, phosphorus, LDL-cholesterol, triglycerides, and inversely correlated with body mass index, femoral neck BMD and total femur BMD (p<0.05). Regarding binary variables, the AACS was associated with previous fragility fractures, current smoking, low physical activity, falls and arterial hypertension (p<0.05). Multiple linear regression analysis demonstrated that the AACS was positively associated with age (p<0.001), current smoking (p<0.001), arterial hypertension (p=0.002), LDL-C (p=0.05), triglycerides (p=0.002), phosphate (p=0.005) and negatively associated with total femur BMD (p<0.001). An increased of AACS was observed with the elevation of serum phosphorus levels [ 2.4mg/dL: AACS=1.9 (SD:3.9); 2.5-3.5mg/dL: AACS=4.5 (SD:5.6) and > 3.5mg/dL: AACS=5.3 (SD:6.3), p=0.003]. Our study identified serum phosphate and hip BMD as additional players in the complex process of vascular calcification outside the setting of kidney failure in community-dwelling older population and extended the previous observations of well-known risk factors for cardiovascular disease

Summary: The FRAX algorithm assesses the patient’s probability of sustaining an osteoporotic fracture and can be calculated with or without densitometric data. This study seeks to determine whether in men, FRAX scores calculated without BMD, correctly identify patients with BMD-defined osteoporosis. Introduction: The diagnosis of osteoporosis is based on densitometric data, the presence of a fragility fracture or increased fracture risk. The FRAX algorithm estimates the patient’s 10-year probability of sustaining an osteoporotic fracture and can be calculated with or without BMD data. The purpose of this study is to determine whether in men, FRAX calculated without BMD, can correctly identify patients with BMD-defined osteoporosis. Methods: Retrospectively retrieved data from 726 consecutive Caucasian males, 50 to 70 years old referred to our Osteoporosis Center. Results: In the population studied, 11.8 and 25.3% had BMD-defined osteoporosis when female and male reference populations were used respectively. When the National Osteoporosis Foundation thresholds to initiate treatment are used, only 27% of patients with BMD-defined osteoporosis, but 4% with normal BMD reached/exceeded these thresholds. Lowering the threshold increased sensitivity, but decreased specificity. Conclusions: Our results suggest that FRAX without BMD is not sensitive/specific enough to be used to identify Caucasian men 50 to 70 years old with BMD-defined osteoporosis.

Sweden and Norway have the worldwide highest incidence of osteoporotic fractures. As these fractures constitute a tremendous and growing problem, primary prevention is of great importance. The principal causes of an osteoporotic fracture are a fall and a fragile skeleton. The aim of the studies reported in these papers was therefore to determine the genetic and environmental influences on fractures and the genetic influence on the two main reasons to the emergence of osteoporotic fractures; bone mineral density and propensity to fall. In the present thesis, we display that the heritability of fractures is dependent on fracture site and age. With increasing age, lifestyle becomes the dominant explanatory factor. These results indicate that focus should be on lifestyle interventions for the prevention of fractures in the elderly. Although the genetic liability to impaired balance is modest, twins with self-reported impaired balance have a substantially increased risk of osteoporotic fractures compared to their co-twin without impaired balance. Asking a patient about his or her balance might be a simple tool for future risk assessment. The genetic influence on bone phenotypes is under strong genetic influence in Swedish adult twins. These findings are in agreement with the results from previous studies in other countries, with a lower incidence of osteoporotic fractures compared to Sweden. The high heritability of bone phenotypes together with the low heritability of fractures at old age, indicates that bone mineral density has a modest influence on fracture risk at old age. In summary, based on the results in this thesis, more emphasis should be targeted to the prevention of falls, by strength and balance training in order to prevent the occurrence of  low energy fractures in the elderly.

Background: The global burden of osteoporosis includes considerable numbers of fractures, morbidity, mortality and expenses, due mainly to vertebral, hip and forearm fractures. Underdiagnosis and undertreatment are common. Several studies have shown decreased health-related quality of life (HRQOL) after osteoporotic fracture, but there is a lack of data from long-term follow-up studies, particularly regarding vertebral fractures, which are often overlooked despite patients reporting symptoms. Aim: The overall aim of this thesis was to evaluate the usefulness of a recent low-energy fracture as index event in a case-finding strategy for osteoporosis and to describe and analyse long-term HRQOL in postmenopausal women with osteoporotic fracture. The specific aims were to describe bone mineral density and risk factors in women 55-75 years of age with a recent low-energy fracture (I), estimate the impact of osteoporotic fractures on HRQOL in women three months and two years after a forearm, proximal humerus, vertebral or hip fracture (II), investigate the changes and long-term impact of vertebral or hip fracture on HRQOL in women prospectively between two and seven years after the inclusion fracture (III), and describe how HRQOL and daily life had been affected in women with vertebral fracture several years after diagnosis (IV). Design and methods: Data were collected from southern Sweden between 1998 and 2008. A total of 303 women were included in Study I, and this group served as the basis for Studies II (n=303), III (n=67), and IV (n=10). A cross-sectional observational, case-control design (I), and a prospective longitudinal observational design (II-III) were used. In Study IV a qualitative inductive approach with interviews was used and data were analysed using a qualitative conventional content analysis. Results: The type of recent fracture and number of previous fractures are important information for finding the most osteoporotic women in terms of severity (I). Hip and vertebral fractures in particular have a significantly larger impact on HRQOL evaluated using the SF-36 than do humerus and forearm fractures, both during the three months after fracture and two years later, compared between the different fracture groups and the reference population (II). Women who had a vertebral fracture as inclusion fracture had remaining pronounced reduction of HRQOL at seven years. At the mean age of 75.5 years (±4.6 SD), the prevalence of vertebral fracture suggests more negative long-term impact on HRQOL, more severe osteoporosis and a poorer prognosis than a hip fracture does, and this effect may have been underestimated in the past (III). Study IV demonstrates that the women’s HRQOL and daily life have been strongly affected by the long-term impact of the vertebral fracture several years after diagnosis. The women strive to maintain their independence by trying to manage different types of symptoms and consequences in different ways. Conclusions and implications: Type and number of fractures should be taken into account in the case-finding strategy for osteoporosis in postmenopausal women between 55 and 75 years of age. The long-term reduction of HRQOL in postmenopausal women (age span 55-75 yr) with vertebral fracture emerged clearly, compared to women with other types of osteoporotic fractures and references in this thesis. The results ought to be taken into consideration when developing guidelines for more effective fracture prevention and treatment, including non-pharmacological intervention for women with osteoporotic fractures, with highest priority placed on vertebral fractures and multiple fractures, to increase or maintain HRQOL.

Rosiglitazone (RSG) is an insulin-sensitizing drug used to treat Type 2 Diabetes Mellitus (T2DM). Clinical trials show that women taking RSG experience more limb fractures than patients taking other T2DM drugs. The purpose of this study is to understand how RSG (3mg/kg/day and 10mg/kg/day) and the bisphosphonate alendronate (0.7mg/kg/week) alter bone quality in the male, female and female ovariectomized (OVX) Zucker fatty rat model over a 12 week period. Bone quality was evaluated by mechanical testing of cortical and trabecular bone. Microarchitecture, bone mineral density (BMD), cortical bone porosity, bone formation/resorption and mineralization were also measured. Female OVX RSG10mg/kg rats had significantly lower vertebral BMD and compromised trabecular architecture versus OVX controls. Increased cortical porosity and decreased mechanical properties occurred in these rats. ALN treatment prevented these negative effects in the OVX RSG model. Evidence of reduced bone formation and excess bone resorption was detected in female RSG-treated rats.

Rosiglitazone (RSG) is an insulin-sensitizing drug used to treat Type 2 Diabetes Mellitus (T2DM). Clinical trials show that women taking RSG experience more limb fractures than patients taking other T2DM drugs. The purpose of this study is to understand how RSG (3mg/kg/day and 10mg/kg/day) and the bisphosphonate alendronate (0.7mg/kg/week) alter bone quality in the male, female and female ovariectomized (OVX) Zucker fatty rat model over a 12 week period. Bone quality was evaluated by mechanical testing of cortical and trabecular bone. Microarchitecture, bone mineral density (BMD), cortical bone porosity, bone formation/resorption and mineralization were also measured. Female OVX RSG10mg/kg rats had significantly lower vertebral BMD and compromised trabecular architecture versus OVX controls. Increased cortical porosity and decreased mechanical properties occurred in these rats. ALN treatment prevented these negative effects in the OVX RSG model. Evidence of reduced bone formation and excess bone resorption was detected in female RSG-treated rats.

The dramatic rise in health care and economic costs as well as increases in morbidity and mortality related to lifestyle behaviors and non-communicable diseases have resulted in an increasing emphasis on research and intervention initiatives aimed at primary prevention. As there is growing evidence that the antecedents of adult diseases such as obesity and osteoporosis have roots in early childhood, physical activity interventions in early childhood (4 to 6 years of age), which has been identified as a critical period, may influence the development of fat and bone mass at this young age and have a potential impact on adolescent and young adult health status and thus improve population health. The intent of this study was to investigate the effects of structured physical activity, specifically early involvement in gymnastics, on early childhood body composition development.<P>Sixty three (25 male and 38 female) 4 to 6 year old children participating in gymnastics programs were compared to 95 control (49 male and 46 female) children. Anthropometric measurements included height, weight, BMI, waist circumference, and skinfold thickness. Dual energy x-ray absorptiometry (DXA) was used to measure whole body bone density and fat mass. Physical activity, physical inactivity, dietary intake, and birth weight of the participants as well as parental heights and weights were also obtained. <P>No significant differences were found, at any age, between the groups in height, weight, BMI, waist circumference, skinfold thickness, physical activity, physical inactivity, dietary intakes, and birth weight or in parental heights and weights (p>0.05). Additionally, there were no significant differences in fat and bone parameters once the confounders of age and size were controlled (p>0.05). <P>This investigation found that young children entering a gymnastics program did not differ in either bone mass or fat mass compared to controls. This was surprising as differences in these parameters have been found in adolescent gymnasts. Thus my results indicate that the potential effects of gymnastics training may have not yet manifested themselves. To answer this question longitudinal measures are required to ascertain whether the body composition differences observed in adolescent gymnasts are due to prolonged exposure to gymnastics involvement.

The dramatic rise in health care and economic costs as well as increases in morbidity and mortality related to lifestyle behaviors and non-communicable diseases have resulted in an increasing emphasis on research and intervention initiatives aimed at primary prevention. As there is growing evidence that the antecedents of adult diseases such as obesity and osteoporosis have roots in early childhood, physical activity interventions in early childhood (4 to 6 years of age), which has been identified as a critical period, may influence the development of fat and bone mass at this young age and have a potential impact on adolescent and young adult health status and thus improve population health. The intent of this study was to investigate the effects of structured physical activity, specifically early involvement in gymnastics, on early childhood body composition development.<P>Sixty three (25 male and 38 female) 4 to 6 year old children participating in gymnastics programs were compared to 95 control (49 male and 46 female) children. Anthropometric measurements included height, weight, BMI, waist circumference, and skinfold thickness. Dual energy x-ray absorptiometry (DXA) was used to measure whole body bone density and fat mass. Physical activity, physical inactivity, dietary intake, and birth weight of the participants as well as parental heights and weights were also obtained. <P>No significant differences were found, at any age, between the groups in height, weight, BMI, waist circumference, skinfold thickness, physical activity, physical inactivity, dietary intakes, and birth weight or in parental heights and weights (p>0.05). Additionally, there were no significant differences in fat and bone parameters once the confounders of age and size were controlled (p>0.05). <P>This investigation found that young children entering a gymnastics program did not differ in either bone mass or fat mass compared to controls. This was surprising as differences in these parameters have been found in adolescent gymnasts. Thus my results indicate that the potential effects of gymnastics training may have not yet manifested themselves. To answer this question longitudinal measures are required to ascertain whether the body composition differences observed in adolescent gymnasts are due to prolonged exposure to gymnastics involvement.