Studies demonstrate short-wavelength cone pathway dysfunction in patients with diabetes and no clinically visible DR. Poor glycemic control, as measured by hemoglobin A1c (HbA1c), is a strong risk factor for DR. We hypothesized that raised HbA1c was associated with short-wavelength cone sensitive visual evoked potential (S-VEP) and electroretinogram (sERG) dysfunction. Forty adolescents with diabetes and 39 controls were tested using the S-VEP. Latencies to a short-wavelength stimulus were delayed in patients at low contrasts. Patient S-VEP latencies were not associated with HbA1c when controlling for age and time since diagnosis. Twenty-one adolescents with diabetes and 19 controls were tested using the sERG. Implicit times of the b-wave were delayed but not associated with HbA1c when controlling for time since diagnosis.Patient PhNR amplitudes were reduced. A one-unit increase in HbA1c was associated with a 15% sERG PhNR amplitude reduction (p=0.004). The sERG PhNR may be a potential biomarker for DR.

Studies demonstrate localized neuro-retinal dysfunction in patients with diabetes and no visible diabetic retinopathy (DR). Poor glycemic control is a strong risk factor for DR. We hypothesized that poor glycemic control predicts increased areas of localized neuro-retinal dysfunction in patients with diabetes. Forty-eight adolescents with diabetes and 45 controls were tested using the standard (103 hexagons) multifocal electroretinogram (mfERG). Negative binomial regression analysis was conducted with number of abnormal hexagons (delayed responses) as the dependent variable and glycated hemoglobin (HbA1c), disease duration, age and sex as covariates. Results indicate that a one-unit increase in HbA1c predicts an 80% (p = 0.002) increase in the number of abnormal hexagons when controlling for age. Increased areas of neuro-retinal dysfunction are predicted by worsening glycemic control in patients with no visible DR. Standard mfERG may be useful in monitoring patients with diabetes and identifying those who may be at risk of developing DR.

Studies demonstrate short-wavelength cone pathway dysfunction in patients with diabetes and no clinically visible DR. Poor glycemic control, as measured by hemoglobin A1c (HbA1c), is a strong risk factor for DR. We hypothesized that raised HbA1c was associated with short-wavelength cone sensitive visual evoked potential (S-VEP) and electroretinogram (sERG) dysfunction. Forty adolescents with diabetes and 39 controls were tested using the S-VEP. Latencies to a short-wavelength stimulus were delayed in patients at low contrasts. Patient S-VEP latencies were not associated with HbA1c when controlling for age and time since diagnosis. Twenty-one adolescents with diabetes and 19 controls were tested using the sERG. Implicit times of the b-wave were delayed but not associated with HbA1c when controlling for time since diagnosis.Patient PhNR amplitudes were reduced. A one-unit increase in HbA1c was associated with a 15% sERG PhNR amplitude reduction (p=0.004). The sERG PhNR may be a potential biomarker for DR.

Diabetes disproportionately affects minority populations. Social support, and more specifically marriage, has been found to buffer the negative effects of diabetes and depression. Data collected from African Americans with type 2 diabetes in Atlanta and NHANES data were compared to examine whether marriage affects health status and mental health. Approximately, 1742 African Americans aged 18-80 were included in this study. Chi square analysis revealed that married men had lower rates of depression (15.9% vs. 24.7%) compared to unmarried men (p < 0.05), but the same effect was not found in women. The findings show that marriage was not associated with HbA1c, but was associated with rates of depression. The lack of association of HbA1c with marriage may be because marriage may not be the best proxy of social support in the African American community. Future research should focus on alternative forms of social support such as cohabitation, extend family, and friend.

Oxidative stress plays a key role in the development of Type 2 Diabetes (T2D). This cross-sectional study examined the relationship among serum levels of manganese superoxide dismutase (MnSOD), 8-hydroxy-2’-deoxyguanosine (8OHdG), dietary antioxidant intakes and glycemic control in African Americans (n=209) and Haitian Americans (n=234) with and without T2D. African Americans had higher BMI (32.8 vs. 29.3 kg/m2), higher energy intake (2148 vs. 1770 kcal), and were more educated as compared to Haitian Americans; all variables were significant at p < .001. Serum levels of 8OHdG and MnSOD for African Americans (1691.0 ± 225.1 pg/ml, 2538.0 ± 1091.8 pg/ml; respectively) were significantly higher than for Haitian Americans (1626.2 ± 222.9, 2015.8 ± 656.3 pg/ml; respectively). 8OHdG was negatively correlated with MnSOD (r = -.167, p < .001) in T2D. Having T2D was negatively correlated with MnSOD (r = -.337; p < .01) and positively correlated with 8OHdG (r = .500; p < .01). African Americans and Haitian Americans with T2D had fasting plasma glucose (FPG) levels of 143.0 ± 61.0 mg/dl and 157.6 ± 65.5 mg/dl, and A1C of 7.5 ± 1.8 % and 8.4 ± 2.4 %, respectively. African Americans and Haitian Americans without T2D had FPG levels of 95.8 ± 13.2 mg/dl and 98.7 ± 16.9 mg/dl, and A1C of 5.9 ± 0.4% and 6.0 ± 0.5%, respectively. Dietary intakes of vitamin C and vitamin D were negatively correlated with FPG (r = -.21; r = -.19, p < .05) respectively. Carotenoids negatively correlated with A1C (r = -.19, p < .05). Lower levels of MnSOD were associated with lower levels of zinc, r = .10, p < .05, and higher levels of carotenoids r = -.10, p < .05. Higher levels of 8OHdG were associated with lower levels of Vitamin D, r = -.14, p < .01, and carotenoids, r = -.09, p < .05. The results demonstrate greater oxidative mtDNA damage in persons with T2D compared to those without T2D and in African Americans compared with Haitian Americans. The inverse relationship between dietary intake of antioxidants and oxidative stress implies a potential to reduce oxidative stress with diet. African Americans were significantly younger (53.3 vs. 55.6 years), had higher BMI (32.8 vs. 29.3 kg/m2), higher energy intake (2148 vs. 1770 kcal), and were more educated as compared to Haitian Americans; all variables were significant at p < .001. Serum levels of 8OHdG and MnSOD for African Americans (1691.0 ± 225.1 pg/ml, 2538.0 ± 1091.8 pg/ml; respectively) were significantly higher than for Haitian Americans (1626.2 ± 222.9, 2015.8 ± 656.3 pg/ml; respectively). 8OHdG was negatively correlated with MnSOD (r = -.167, p < .001) in T2D. Having T2D was negatively correlated with MnSOD (r = -.337; p < .01) and positively correlated with 8OHdG (r = .500; p < .01). African Americans and Haitian Americans with T2D had fasting plasma glucose (FPG) levels of 143.0 ± 61.0 mg/dl and 157.6 ± 65.5 mg/dl, and A1C of 7.5 ± 1.8 % and 8.4 ± 2.4 %, respectively. African Americans and Haitian Americans without T2D had FPG levels of 95.8 ± 13.2 mg/dl and 98.7 ± 16.9 mg/dl, and A1C of 5.9 ± 0.4% and 6.0 ± 0.5%, respectively. Dietary intakes of vitamin C and vitamin D were negatively correlated with FPG (r = -.21; r = -.19, p < .05) respectively. Carotenoids negatively correlated with A1C (r = -.19, p < .05). Lower levels of MnSOD were associated with lower levels of zinc, r = .10, p < .05, and higher levels of carotenoids r = -.10, p < .05. Higher levels of 8OHdG were associated with lower levels of Vitamin D, r = -.14, p < .01, and carotenoids, r = -.09, p < .05. The results demonstrate greater oxidative mtDNA damage in persons with T2D compared to those without T2D and in African Americans compared with Haitian Americans. The inverse relationship between dietary intake of antioxidants and oxidative stress implies a potential to reduce oxidative stress with diet.

Background: Diabetes self-management education, including nutrition education (NE) is an essential component of diabetes management. Effective NE can assist individuals with type 2 diabetes mellitus (DM) in resource limited settings to improve their dietary self-care; an area cited among the most difficult with consequent improvement in health outcomes. Aim: To develop a NE programme that is tailored to the needs of adults with type 2 DM in a resource limited setting and to evaluate the programme's effectiveness on health outcomes. Setting: Makapanstad and Mathibestad community health centres in the Moretele sub-district, North West Province (South Africa). Methods: The study was done in three phases employing mixed methods research. Qualitative methods, using focus group discussions with 31 diabetic patients (a convenience purposive sample), and an open ended self-administered questionnaire with ten health professionals serving them, assessed the NE needs and preferences (phase 1). The data were analysed according to the framework approach. The results from the needs assessment were used to plan a tailored NE programme (phase 2). A randomised controlled trial (quantitative) with a sample of 82 patients (with HbA1c ≥ 8), allocated to either intervention or control groups, evaluated the effect of the NE programme (phase 3). Outcomes [HbA1c, dietary behaviours, blood lipids, blood pressure, body mass index (BMI), diabetes knowledge and attitudes towards diabetes and its treatment] were assessed at baseline, six months and 12 months respectively. An analysis of covariance (ANCOVA) compared the groups on measured outcomes using baseline values, age, gender, and clinic as covariates. Rank ANCOVA was used for dietary intake. The level of significance for all tests was set at α < 0.05 for a two-tailed test. Results: Needs assessment Diabetes related knowledge deficits and inappropriate dietary practices, including food portion control problems, inadequate intake of vegetables and fruits and unbalanced diets, were observed. Eight barriers and two facilitators to dietary adherence were identified. Financial constraint was the major barrier while social support was the major facilitator. NE recommendations included content related to the disease and diet, group education at the clinic, a competent educator, provision of education materials and inclusion of family members. The planned NE programme consisted of eight weekly training sessions and six follow-up sessions (monthly and bi-monthly), vegetable gardening demonstrations and education materials. Nutrition education programme effects: Seventy six participants (38 per group) completed the study. The differences in HbA1c (primary outcome) between the intervention and control groups were -0.62% (p=0.15) at six months and -0.67% (p=0.16) at 12 months. Few participants, four from the intervention group and one from the control group, achieved HbA1c target (<7%) at both six and 12 months, [(p=0.20), (p=0.36)] respectively. There were no significant between group differences in BMI, lipid profile and blood pressure at six months and 12 months. Starchy foods intake (median servings) were significantly lower in the intervention group compared to the control group, 9.3 vs. 10.8 (p=0.005) at six months and 9.9 vs. 11.9 (p=0.017) at 12 months. The proportion of participants growing own vegetables significantly increased in the intervention group compared to the control group 17/41 vs. 5/40 (p=0.003) at six months and 16/38 vs. 5/38 at 12 months. No significant group differences in the intake of energy, macronutrients, vegetable and fruits, sodium, cholesterol and fibre were observed at six and 12 months. Diabetes knowledge improved in the intervention group +0.95 (p=0.033) and +2.2 (p=0.000) when compared with the control group at six and 12 months respectively. There were no significant group differences in the attitudes towards diabetes and its treatment. Conclusions: The qualitative needs assessment provided insight for planning a tailored NE programme. The NE improved some dietary behaviours (starchy foods portion control and growing own vegetables) and diabetes knowledge. A non-significant lowering of HbA1c was observed. / Thesis (Phd)--University of Pretoria, 2013. / Human Nutrition / unrestricted

No description available.

Background: African-Americans are a vulnerable population group with disproportionately elevated rates of type 2 Diabetes Mellitus (DM). Resistant starch is a promising food ingredient that has the potential to reduce the risk factors involved in the development of type 2 DM. To date, there is a dearth of published research studies on the effect of resistant starch on African-Americans who are at increased risk for type 2 DM. Objective: The major objective of this study was to determine if daily consumption of approximately twelve grams of high-maize™ 260 resistant starch (RS) added to bread improved glucose homeostasis by monitoring changes in fasting plasma glucose, fructosamine, hemoglobin A1c, insulin, glucagon-like peptide-1, C-reactive protein, homeostasis model assessment insulin resistant (HOMA- IR) and beta-cell function (HOMA-Beta), serum acetate, propionate, and butyrate levels. Design: A fourteen-week, randomized, double-blind, within-subject crossover design feeding study was carried out in African-American males (n=8) and females (n=7) at increased risk for type 2 DM who resided in Southwest Virginia. All participants consumed bread containing added RS or control bread (no added RS) for six-weeks. RS and control bread feedings were separated by a two-week washout period. Results: Fasting Plasma Glucose (FPG) levels were significantly lower (P = 0.0179) after six-week control bread feedings compared to baseline. FPG levels were also significantly lower (P < 0.0001) after two-week washout period than at baseline. FPG levels were significantly higher (P < 0.0001) after six-week resistant starch bread feeding than at washout. FPG levels due to consumption of resistant starch versus control bread approached significance (P = 0.0574). Fructosamine levels were significantly lower (P = 0.0054) after control bread and resistant starch bread (P < 0.0012) consumption compared to baseline. No significant differences were found in fructosamine levels due to resistant bread intake versus control (P = 0.9692). Mean baseline HbA1c levels were 6.9% (n=15). This value was slightly lowered to 6.79% (n=14) at the end of the fourteen-week study, although statistical significance was not found. Mean ± standard errors for HbA1c values were 6.9% ± 0.18% and 6.9% ± 0.14% at baseline for the sequence groups, resistant starch first (n=7) and control treatment first (n=8) groups, respectively. Mean± standard error HbA1c values were 6.7%± 0.27% and 6.9% ± 0.27% at the conclusion of fourteen-week study for sequence groups, resistant starch first group (n=7) and control treatment first group, respectively. Baseline mean and standard errors C-reactive Protein (CRP) levels for male and female combined results were 0.62 ± 0.16 mg/dL (n=15). Mean CRP levels were 0.53 ± 0.12 mg/dL for resistant starch bread and 0.64 ± 0.21 mg/dL for control bread feeding periods. No significant differences were found for treatment, gender, or sequence effects for C-reactive protein levels during the fourteen-week study (P > 0.05). Mean HOMA-IR levels following six-week resistant starch and control bread consumption decreased to normal values (> 2.5), although no significant differences were found for treatment (P = 0.5923). Conclusions: Eighty-seven grams of Hi- maize™ 260 Resistant Starch added to baked loaves of bread consumed by a free-living African-American population at increased risk for type 2 diabetes did not consistently show significance in all clinical indicators and biochemical markers assessed. On the basis of the evidence in this study we do not have evidence that this amount of resistant starch in this population's diet will prevent the onset of diabetes. However, results are suggestive that higher levels of resistant starch in a more controlled experiment could reduce clinical risk factors for type 2 diabetes. / Ph. D.