Abstract inserted as part of Final MPH Thesis: Non-Communicable Diseases like diabetes, cardiovascular diseases, cancers and others, have become the major cause of premature death, morbidity and disability in many Pacific countries including Samoa. These are linked by common preventable risk factors like obesity, hypertension, smoking, unhealthy diets and physical inactivity. OBJECTIVES: To determine the trends and development of Non-Communicable diseases and its risk factors in Samoa over the last 24 years using the recently developed diagnostic criteria. RESEARCH DESIGN AND METHODS: This research thesis combines 3 large surveys that were done in 1978, 1991, and 2002, looking at the trends in the prevalence of diabetes, and the prevalence of the NCD risk factors such as blood pressure, obesity, cholesterol and smoking. The 3 survey samples were selected randomly from around similar regions (Urban Upolu, Rural Upolu, and Rural Savaii) of Samoa in 1978, 1991 and 2002, with a total of 5973 individuals (1978 survey = 1467; 1991 survey = 1778; 2002 survey = 2728) available for the thesis analysis. The 1978 and 1991 data sets were secured from Professor P Zimmet, and the 2002 STEPs survey data set was secured from the Samoa Ministry of Health. The 3 surveys methodologies, survey procedures, questionnaires and anthropometric measurements were similar though the diagnostic criteria used to measure obesity slightly differ between the surveys. The blood pressure measurements were similar though the diastolic blood pressure measure in 1978 was higher. The 1978 and 1991 surveys used fasting venous blood sampling to measure fasting plasma glucose, and cholesterol levels at the laboratory. OGTT was also used in 1978 and 1991, but not 2002. The 2002 survey used capillary sampling to measure fasting glucose using a glucometer, and cholesterol level using a cholesterol meter. The combined data was then cleaned, standardized and matched with each survey, to make analysis easier. The recent diagnostic criteria were then applied to all the surveys to diagnose diabetes (1999 WHO Diabetes Criteria), hypertension (WHO 1999, JNC-VII 2003, NHF 1999 Hypertension Criteria), obesity (BMI ≥30 kg/m??), and hypercholesterolaemia. The prevalences using the recent diagnostic criteria were then mapped out. RESULTS: The overall age-standardized prevalence of type 2 diabetes (known or previously unknown) utilizing the current 1999 WHO diagnostic criteria for men and women ≥20 years of age has increased from 5.4% (males 4.8%, females 5.9%) in 1978, to 12.0% (males 10.9%, females 13.5%) in 1991, and to 20.1% (males 17.2%, females 22.2%) in 2002. Among the individuals with diabetes in the 3 surveys, more than 60% had previously undiagnosed diabetes. Compared with the 1978 survey, the diabetes prevalence in 2002 represents a 4-fold increase over the 24 year period. This has occurred along with increasing obesity, urbanization and modernization, aging, cultural changes, and changes in physical activity. There is a high prevalence of non-communicable disease risk factors. The age-standardized prevalence of hypertension defined by the WHO 1999 and JNC-VII 2003 criteria was 47.2% in 1978, 22.5% in 1991, and 24.0% in 2002. The high prevalence of hypertension in 1978 was due to the method used for recording diastolic blood pressure. Hypertension was more common in the urban regions than rural regions in 1978 and 1991 while in 2002, there was no statistical difference between the rates of hypertension between the different regions due to the rise in the prevalence rate of hypertension in rural regions. There is a high prevalence of overweight and obesity in Samoa. Using the WHO classification for BMI, there was an increase in obesity (BMI ≥ 30kg/m??) prevalence in Samoa in the last decade, increasing steeply from 34.9% in 1978 to 51.3% in 1991, and slowing down to an increase to 57.4% in 2002. The prevalence of obesity is significantly higher in females compared with their male counterparts. The overweight prevalence (BMI 25-29.9kg/m??) was 34% in 1978, 31% in 1991 and 29% in 2002. The prevalence of obesity has increased by 65% from 1978 to 2002 with an increase of 47% from 1978 to 1991, and 12% from 1991 to 2002. Prevalence of obesity is increasing with age and is more of a problem in women than men. It is higher in the urban regions but there has been a faster rise in obesity prevalence in rural regions from 1978 to 2002 as the rural regions become urbanized. The prevalence of hypercholesterolaemia (total cholesterol ≥ 5.2 mmol/l) was 30.5% in 1978, and this increased to 51.1% in 1991. There was a marked decline of hypercholesterolaemia in 2002 (14.4%), which may be due to differences in the method of measurement. Although smoking prevalence remains high in Samoa it declined significantly from 42.4% 1978 to 35.3% 1991 but remained essentially steady at 38% in 2002. There was a significant gender difference in smoking with about 60% of men and 20% of women smoking regularly. CONCLUSION: Samoa is experiencing an increasing problem with Non-Communicable diseases like diabetes and some of its risk factors. Diabetes prevalence has dramatically increased by 4-fold in the last 24 years. The prevalence of hypertension has stabilized around 23% though there was a decrease from 1978. The prevalence of obesity has also increased. Smoking prevalence has slightly increased from 1991 to 2002 with a significant number of the population smoking. Hypercholesterolaemia is more common in 1991 with an apparent decrease in 2002. These findings have important implications for public health efforts and policy developments to contain the epidemic of Non-Communicable diseases in Samoa.
| Identifer | oai:union.ndltd.org:ADTP/272465 |
| Date | January 2009 |
| Creators | Viali, Satupaitea, Public Health & Community Medicine, Faculty of Medicine, UNSW |
| Publisher | Awarded By:University of New South Wales. Public Health & Community Medicine |
| Source Sets | Australiasian Digital Theses Program |
| Language | English |
| Detected Language | English |
| Rights | http://unsworks.unsw.edu.au/copyright, http://unsworks.unsw.edu.au/copyright |
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