Ethnic disparities in the association of impaired fasting glucose with the 10-year cumulative incidence of type 2 diabetes.

AIMS: Evidence of ethnic disparities in the conversion of prediabetes to type 2 diabetes is scarce. We studied the association of impaired fasting glucose (IFG) and fasting plasma glucose (FPG) with the 10-year cumulative incidence of type 2 diabetes in three ethnic groups. METHODS: We analyzed data for 90 South-Asian Surinamese, 190 African-Surinamese, and 176 ethnic Dutch that were collected in the periods 2001-2003 and 2011-2012. We excluded those with type 2 diabetes or missing FPG data. We defined baseline IFG as FPG of 5.7-6.9 mmol/L. We defined type 2 diabetes at follow-up as FPG ≥ 7.0 mmol/L, HbA1c ≥ 48 mmol/mol (6.5%), or self-reported type 2 diabetes. RESULTS: 10-Year cumulative incidences of type 2 diabetes were: South-Asian Surinamese, 18.9%; African-Surinamese, 13.7%; ethnic Dutch, 4.5% (p<0.05). The adjusted association of baseline IFG and FPG with the 10-year cumulative incidence of type 2 diabetes was stronger for South-Asian Surinamese than for African-Surinamese and ethnic Dutch. The IFG (compared to normoglycaemia) ORs were 11.1 [3.0-40.8] for South-Asian Surinamese, 5.1 [2.0-13.3] for African-Surinamese, and 2.2 [0.5-10.1] for ethnic Dutch. CONCLUSIONS: The 10-year cumulative incidence of type 2 diabetes was higher and associations with baseline IFG and FPG were stronger among South-Asian Surinamese and African-Surinamese than among ethnic Dutch. Our findings confirm the high risk of type 2 diabetes in South-Asians and suggest more rapid conversion in populations of South-Asian origin and (to a lesser extent) African origin than European origin.

Ethnicity influences weight loss 1 year after bariatric surgery: a study in Turkish, Moroccan, South Asian, African and ethnic Dutch patients.

Several studies conducted in the USA have demonstrated that the effectiveness of bariatric surgery differs between patients from African and European origin. However, little is known on differences in outcomes after bariatric surgery between individuals from other ethnic backgrounds. In this retrospective study, we found that, in terms of weight loss, gastric bypass surgery is less effective in African, South Asian, Turkish and Moroccan patients than in their ethnic Dutch counterparts. Our results underscore that ethnic differences in the effectiveness of bariatric surgery are not limited to those between patients of African and European origin, but extend to other minority groups as well. Therefore, it is important that prospective studies both determine ethnic differences in weight loss-related improvement of co-morbidities and elucidate the exact reasons for these ethnic disparities.

Cold-induced activity of brown adipose tissue in young lean men of South-Asian and European origin.

AIMS/HYPOTHESIS: South Asians have a disproportionately high risk of developing abdominal obesity, insulin resistance and type 2 diabetes. Brown adipose tissue (BAT) has been identified as a possible target to fight obesity and protect against metabolic disturbance. We explored whether lower BAT activity in South Asians compared with Europids may contribute to the high risk of metabolic disturbance. METHODS: We studied 20 healthy men (ten Europids/ten South Asians, BMI 19-25 kg/m(2), age 18-32 years). Following 2 h of cold exposure (16-18°C) after an overnight fast, (18)F-fluorodeoxyglucose ((18)F-FDG) positron-emission tomography-computed tomography (CT) and (123)I-metaiodobenzylguanidine ((123)I-MIBG) single-photon emission computed tomography-CT were performed to visualise metabolic BAT activity and sympathetic stimulation of BAT. Metabolic BAT activity was defined as maximal standardised uptake value (SUV(max)) of (18)F-FDG, and sympathetic stimulation of BAT as semiquantitative uptake value (SQUV) of (123)I-MIBG. We performed hyperinsulinaemic-euglycaemic clamps to assess insulin sensitivity. Spearman's correlations for SUV(max) of (18)F-FDG and both SQUV of (123)I-MIBG and insulin sensitivity were determined. RESULTS: The median (interquartile range) SUV(max) of (18)F-FDG in South Asians (7.5 [2.2-10.6] g/ml) was not different from the median SUV(max) obtained in Europids (4.5 [2.2-8.4] g/ml; p = 0.59). There was no correlation between BAT activity and insulin sensitivity. Correlations between SQUV of (123)I-MIBG and SUV(max) of (18)F-FDG were positive, both in the total population (ρ = 0.80, p < 0.001) and after stratification by ethnicity (Europids, ρ = 0.65, p = 0.04; South Asians, ρ = 0.83, p = 0.01). CONCLUSIONS/INTERPRETATION: This is the first study to prospectively investigate ethnic differences in metabolic BAT activity during cold exposure. We did not find differences in BAT activity between South Asians and Europids. Therefore, it seems unlikely that BAT plays an important role in the development of unfavourable metabolic profiles in South Asians.

The association of physical inactivity with Type 2 diabetes among different ethnic groups.

AIMS: To study differences in the association between physical inactivity and Type 2 diabetes among subjects from different ethnic groups. METHODS: We analysed data on 508 Caucasian, 596 African-Surinamese and 339 Hindustani-Surinamese participants, aged 35-60 years, in the population-based, cross-sectional Surinamese in the Netherlands Study on Health and Ethnicity (SUNSET) study. Physical inactivity was defined as the lowest quartile of reported activity, measured with the validated Short Questionnaire to Assess Health-Enhancing Physical Activity. Type 2 diabetes was defined as fasting plasma glucose levels ≥7.0 mmol/l or self-reported diagnosis. RESULTS: Physical inactivity was associated with Type 2 diabetes (OR 1.63, 95% CI 1.12-2.38) in the total group after adjustment for sex, age, BMI, ethnicity, resting heart rate, hypertension, smoking, history of cardiovascular disease, having a first-degree relative with Type 2 diabetes and educational level. However, this association was only significant in Caucasians (OR 3.17, 95% CI 1.37-7.30). Moreover, it appeared stronger in Caucasians than in Hindustani-Surinamese (OR 1.43, 95% CI 0.78-2.63) and African-Surinamese (OR 1.13, 95% CI 0.58-2.19), although the P-value for interaction was not significant. CONCLUSIONS: Physical inactivity was associated with Type 2 diabetes in the total group after adjustment for multiple risk factors, but this association was only significant in Caucasians. Also, it appeared stronger in Caucasians than in Hindustani and African-Surinamese, but formal testing for interaction provided no further evidence. These findings confirm the importance of exercise, but suggest that potential health gain may differ between ethnic groups. However, it should be noted that, in general, promotion of physical activity in populations with an increased a priori risk of Type 2 diabetes, remains of the utmost importance.