Estimating the changing burden of disease attributable to high fasting plasma glucose in South Africa for 2000, 2006 and 2012.

BACKGROUND: Worldwide, higher-than-optimal fasting plasma glucose (FPG) is among the leading modifiable risk factors associated with all- cause mortality and disability-adjusted life years (DALYs) due to the direct sequelae of diabetes and the increased risk for cardiovascular and chronic kidney disease. OBJECTIVES: To report deaths and DALYs of health outcomes attributable to high FPG by age and sex for South Africa (SA) for 2000, 2006 and 2012. METHODS: Comparative risk assessment methodology was used to estimate the burden attributable to high FPG. A meta-regression analysis was performed using data from national and small-area studies to estimate the population distribution of FPG and diabetes prevalence. Attributable fractions were calculated for selected health outcomes and applied to local burden estimates from the second South African National Burden of Disease Study (SANBD2). Age-standardised rates were calculated using World Health Organization world standard population weights. RESULTS: We estimated a 5% increase in mean FPG from 5.31 (95% confidence interval (CI) 5.18 - 5.43) mmol/L to 5.57 (95% CI 5.41 - 5.72) mmol/L and a 75% increase in diabetes prevalence from 7.3% (95% CI 6.7 - 8.3) to 12.8% (95% CI 11.9 - 14.0) between 2000 and 2012. The age-standardised attributable death rate increased from 153.7 (95% CI 126.9 - 192.7) per 100 000 population in 2000 to 203.5 (95% CI 172.2 - 240.8) per 100 000 population in 2012, i.e. a 32.4% increase. During the same period, age-standardised attributable DALY rates increased by 43.8%, from 3 000 (95% CI 2 564 - 3 602) per 100 000 population in 2000 to 4 312 (95% CI 3 798 - 4 916) per 100 000 population in 2012. In each year, females had similar attributable death rates to males but higher DALY rates. A notable exception was tuberculosis, with an age-standardised attributable death rate in males double that in females in 2000 (14.3 v. 7.0 per 100 000 population) and 2.2 times higher in 2012 (18.4 v. 8.5 per 100 000 population). Similarly, attributable DALY rates were higher in males, 1.7 times higher in 2000 (323 v. 186 per 100 000 population) and 1.6 times higher in 2012 (502 v. 321 per 100 000 population). Between 2000 and 2012, the age-standardised death rate for chronic kidney disease increased by 98.3% (from 11.7 to 23.1 per 100 000 population) and the DALY rate increased by 116.9% (from 266 to 578 per 100 000 population). CONCLUSION: High FPG is emerging as a public health crisis, with an attributable burden doubling between 2000 and 2012. The consequences are costly in terms of quality of life, ability to earn an income, and the economic and emotional burden on individuals and their families. Urgent action is needed to curb the increase and reduce the burden associated with this risk factor. National data on FPG distribution are scant, and efforts are warranted to ensure adequate monitoring of the effectiveness of the interventions.

Perspectives on gestational diabetes mellitus in South Africa.

The field of gestational diabetes mellitus has attracted increasing attention and research in South Africa (SA) over the past decade, creating a better understanding of the disease burden, risk factors, availability of specialised healthcare services, and importantly the far-reaching maternal and childhood consequences beyond the pregnancy. This article brings together all the local published literature in the field and outlines the implications of this condition, together with recommendations regarding particular areas that require attention in order to prevent and alleviate the disease burden in SA.

Sugar-sweetened beverage intake and relative weight gain among South African adults living in resource-poor communities: longitudinal data from the STOP-SA study.

OBJECTIVES: This study examines the prospective association between sugar-sweetened beverages (SSB) consumption and change in body weight over a 4-5-year period in a socio-economically disadvantaged South African population. METHODS: This is a longitudinal study involving 800 adults (212 men, 588 women); 247 from the original METS (Modelling the Epidemiological Transition Study) cohort (N = 504) and 553 of the original 949 members of the PURE (Prospective Urban and Rural Epidemiology) Study. Both cohorts were drawn from low-income, socio-economically disadvantaged communities. Mean follow-up duration and age were 4.5 (SD 0.45) and 50.0 (SD 11.8) years, respectively. Harmonised measurements included body mass index, self-reported moderate-to-vigorous physical activity, and intake of meat, snacks and 'take-aways', fruits and vegetables and SSB (in servings/week). Multivariate logistic regression models were developed to determine the extent to which SSB consumption predicted relative weight gain, after controlling for potential confounders and known predictors. RESULTS: Nearly a third (29%) of participants had a relative weight change ≥5.0%; higher in the non-obese compared to the obese group (32% vs. 25%; p = 0.026). The average SSB consumption was 9.9 servings/week and was higher in the food insecure compared to the food secure group (11.5 vs. 9.0 servings/week; p = 0.006); but there were no differences between women and men (10.3 vs. 9.1 servings/week; p = 0.054). Mean SSB consumption was higher in the group who gained ≥5% weight compared to those who did not (11.0 vs. 8.7; p = 0.004). After adjustment, SSB consumption of 10 or more servings/week was associated with a 50% greater odds of gaining at least 5% body weight (AOR: 1.50, 95% CI (1.05-2.18)). CONCLUSION: These results show that higher intake of SSB predicts weight gain in a sample of South Africans drawn from low-income settings. Comprehensive, population-wide interventions are needed to reduce SSB consumption in these settings.

Site-specific differences in bone mineral density in black and white premenopausal South African women.

SUMMARY: We examined ethnic differences in bone mineral density (BMD) and the contribution of body composition, lifestyle and socioeconomic factors in South African women. Femoral neck and total hip BMD were higher, but lumbar spine BMD was lower in black women, with body composition, lifestyle and socioeconomic status (SES) factors contributing differently in ethnic groups. INTRODUCTION: There is a paucity of data on the relative contribution of body composition, lifestyle factors and SES, unique to different ethnic groups in South Africa, to BMD. We examined differences in femoral neck (FN), total hip (TH) and lumbar spine (LS) BMD between black and white premenopausal South African women and the associations between BMD and body composition, lifestyle factors and SES in these two ethnic groups. METHODS: BMD and body composition were measured in 240 black (27 ± 7; 18-45 years) and 187 white (31 ± 8; 18-45 years) women using dual-energy X-ray absorptiometry. Questionnaires were administered to examine SES, physical activity and dietary intake. RESULTS: After co-varying for age, FN and TH were higher in black than white women (FN 0.882 ± 0.128 vs. 0.827 ± 0.116 g/cm(2), P < 0.001; TH 0.970 ± 0.130 vs. 0.943 ± 0.124 g/cm(2), P = 0.018). When adjusting for ethnic differences in body composition, LS was higher in white than black women. In black women, fat-free soft tissue mass, SES and injectable contraceptive use explained 33-42% of the variance in BMD at the hip sites and 22% at the LS. In white women, fat-free soft tissue mass and leisure activity explained 24-30% of the variance in BMD at the hip sites, whereas fat mass, leisure activity and oral contraceptive use explained 11% of the variance at the LS. CONCLUSION: FN and TH BMD were higher, but LS BMD was lower in black than white South African women with body composition, lifestyle and SES factors contributing differently to BMD in these women.

Total daily energy expenditure in black and white, lean and obese South African women.

BACKGROUND/OBJECTIVES: In South Africa (SA), the prevalence of obesity in women is 56%, with black women being most at risk (62%). Studies in the United States have demonstrated ethnic differences in resting (REE) and total daily energy expenditure (TDEE) between African American (AA) and their white counterparts. We investigated whether differences in EE exist in black and white SA women, explaining, in part, the ethnic obesity prevalence differences. SUBJECTS/METHODS: We measured REE, TDEE and physical activity EE (PAEE) in lean (BMI <25 kg m(-2)) and obese (BMI >30 kg m(-2)) SA women (N=44, 30+/-6 year). REE, TDEE, PAEE and total awake EE were measured during a 21 h stay in a respiration chamber. RESULTS: Black and white subjects within obese and lean groups were not significantly different for age, mass, BMI and % body fat. However, fat-free mass (kg FFM) was consistently lower in the black women (P<0.01) in both weight groups. After adjusting EE measurements for differences in FFM, REE was not significantly different for either body weight or ethnicity, although 24 h TDEE (kJ) was significantly greater in the obese women (P<0.01) and white women (P<0.05). Total awake non-PAEE was not significantly different for either groups, while total awake time was only significantly lower for the lean groups (P<0.01). Total PAEE (kJ min(-1)) was significantly lower in the lean (P<0.001) and black groups (P<0.01). CONCLUSIONS: In this sample of matched, lean and obese, black and white SA women, differences in TDEE were largely explained by ethnic differences in PAEE, and were not as a result of ethnic differences in REE.

Diabetes in Africa: epidemiology, management and healthcare challenges.

Diabetes is an increasing problem in sub-Saharan Africa. Type 2 diabetes, the most common form, is becoming more prevalent owing to rising rates of obesity, physical inactivity and urbanisation. Type 1 diabetes exists in two major forms in the region: type 1A or autoimmune and type 1B or ketosis-prone type 2 diabetes. At present there are scanty epidemiological data on either. The current morbidity of diabetes is primarily due to the high rates of microvascular complications, while macrovascular complications, once rare, are becoming more common, particularly in the urban setting. Further, despite the HIV epidemic, the total number of people with diabetes in the region is expected to grow because of changing demography. A concerted multisectoral effort will be critical to ensuring improvement in healthcare delivery for people with diabetes in the region.

Hyperglycaemic emergency admissions to a secondary-level hospital - an unnecessary financial burden.

BACKGROUND AND OBJECTIVES: Diabetes affects approximately 1 million South Africans. Hospital admissions, the largest single item of diabetes expenditure, are often precipitated by hyperglycaemic emergencies. A recent survey of a 200- bed hospital, serving approximately 1.3 million Cape Town residents, showed that hyperglycaemic emergencies comprised 25.6% of high-care unit admissions. A study was undertaken to determine the reasons for, and financial cost of, these admissions. METHODS: All hyperglycaemic admissions during a 2-month period (1 September - 31 October 2005) were surveyed prospectively. Admissions were classified using the American Diabetes Association classification of hyperglycaemic emergencies. Demographic data, and the reason for, duration of and primary outcome of admission, were recorded. The following costs per admission were calculated using publicsector pricing: (i) total costs; (ii) patient-specific costs; (iii) nonpatient- specific costs; and (iv) capital costs. RESULTS: Sepsis (36%), non-compliance with therapy (32%) and a new diagnosis of diabetes (11%) were the predominant reasons for admission of 53 hyperglycaemic emergency cases. Mean duration of hospital stay was 4 days, with an in-hospital mortality of 7.5%. Mean cost per admission was R5 309. Clinical staff (25.8%), capital (25.6%) and overhead (34%) costs comprised 85.4% of expenditure. DISCUSSION AND RECOMMENDATIONS: Hyperglycaemic admissions, costing more than R5 300 per patient, represent a health burden that has remained unchanged over the past 20 years. Urgently required primary care preventive strategies include early diagnosis of diabetes, timely identification and treatment of precipitating causes, specifically sepsis, and education to improve compliance.