The relationship between anthropometry, dietary intake and type 2 diabetes mellitus in women (25-44 years) in Mangaung

Thesis

South Africa, like many other countries, is a country in transition, leading to pol ~ical, demographic, social, economical, and nutritional changes, affecting particularly the African population. This new era is characterised by changes from the trad~ional lifestyle, to a more westem lifestyle and eating habits, associated with chronic diseases of lifestyle, including type 2 diabetes mellitus. Type 2 diabetes mell~us, which affects an increasing number of people in South Africa, including the African population, is characterised by insulin resistance, a dysfunction of the insulin secreting beta cells of the pancreas, and reduced receptor binding characteristics, leading to high blood glucose levels, and metabolic abberations. Risk factors for this disease include aging, gender, genetiC factors, change in lifestyle factors, socio-economic factors, obesity, and some metabolic disorders. The serious health complications associated with type 2 diabetes, emphasise the need to address this disease urgently. The effect of the nutrition transition, including the increase in chronic diseases of lifestyle, has prompted the need to determine the association between anthropometry, dietary intake and type 2 diabetes mellitus. A representative sample of 500 African women, (age groups 25-34, and 35-44 years), from the Mangaung area of Bloemfontein, was selected for the study. The soci<HIemographic composition of the subjects was determined by means of a questionnaire. Weight, height, circumference (waist and hip), and bio-impedance measurements were obtained, and used to calculate body mass index, fat distribution and fat percentage of respondents. Dietary intake was determined by means of a standardised food frequency questionnaire, and analysed to determine the habitual food intake of respondents. Blood samples were collected to determine the triglyceride, total cholesterol, serum albumin, serum glucose, and serum insulin status of each subject. Anthropometric results included body mass index, fat distribution and fat percentage. More than fifty percent of respondents had a body mass index above 25. Fat distribution showed a gynoid fat distribution, with 83.5 percent of the women from the younger group, and 62.7 percent of women from the older group having a waist-hip-ratio smaller than 0.8. The fat percentages of women from both age groups were high. From the younger women, 92.5 percent, and from the older women 94 percent showed fat percentages that exceeded the normal fat percentage. Median dietary intakes indicated high intakes for energy, macro-nutrients and cholesterol. Median intakes of the macro-nutrients and cholesterol calculated as percentage of the total daily energy intake showed that median percentage of protein, saturated fats, mono-unsaturated fats, and pOly-unsaturated fats fell within recommendations, while median percentage of total fat intake exceeded recommendations. Median intakes of chromium, potassium, manganese, and phosphorus were high. Low median intakes were reported for calcium, total iron, copper and selenium, vitamins A, C, D, E and folate. The thirty most frequently consumed foods by mass, indicated that although traditional foods are still popular, more Westem foods and beverages are also being chosen. Biochemical parameters indicated that most women from the two age groups had normal fasting triglycerides, serum albumin, serum glucose and serum insulin levels, while fasting cholesterol levels seemed to increase with an increase in age. Although the prevalence of type 2 diabetes in this population was low, a significant risk for the development of diabetes was identified, as indicated by the significant association between insulin sensitivity and body mass index, and the association between insulin resistance and triglycerides. Reverting to a more traditional lifestyle, including diet and physical activity, could assist in alleviating the conditions of over-and under nutrition, and unfavourable anthropometric and biochemical parameters associated with the health status of these African women.