Prevalence of NIDDM Among Populations of the African Diaspora

Abstract

OBJECTIVE -Rates of non-insulin-dependent diabetes mellitus have risen sharply in recent years among blacks in the U.S. and the U.K. Increases in risk have likewise been observed in the island nations of the Caribbean and in urban West Africa. To date, however, no systematic comparison of the geographic variation of NIDDM among black populations has been undertaken. RESEARCH DESIGN AND METHODS-In the course of an international collaborative study on cardiovascular disease, we used a standardized protocol to determine the rates of NIDDM and associated risk factors in populations of the African diaspora. Representative samples were drawn from sites in Nigeria, St. Lucia, Barbados, Jamaica, the United States, and the United Kingdom. A total of 4,823 individuals aged 25-74 years were recruited, all sites combined.RESULTS -In sharp contrast to a prevalence of 2% in Nigeria, age-adjusted prevalences of self-reported NIDDM were 9% in the Caribbean and 11% in the U.S. and the U.K. Mean BMI ranged from 22 kg/m 2 among men in West Africa to 31 kg/m 2 in women in the U.S. Disease prevalence across sites was essentially collinear with obesity, pointing to site differences in the balance between energy intake and expenditure as the primary determinant of differential NIDDM risk among these populations.CONCLUSIONS -In ethnic groups sharing a common genetic ancestry, these comparative data demonstrate the determining influence of changes in living conditions on the population risk of NIDDM.

Genetic Research and Health Disparities

“…Research instead shows far lower rates of these conditions. [45][46][47][48][49][50] One explanation proposed to explain the different rates of hypertension and diabetes in black Africans and black Americans 51,52 is that new environments encountered in the African diaspora triggered expression of certain genetic variations quiescent in Africa. Even if this explanation is correct, the heterogeneity and variability of the environments encountered make it unlikely that the direction of this triggering was nearly always to confer on blacks ill health, especially considering the widely variable conditions, such as breast cancer, depression, and diabetes, that unequally affect them.…”

Overweight and obesity among Ghanaian residents in The Netherlands: how do they weigh against their urban and rural counterparts in Ghana?

“…Understanding the mechanism underlying the increasing prevalence of overweight and obesity among ethnic minority people is crucial for appropriate intervention strategies for prevention. Earlier studies comparing various populations of African descent in diverse geographical settings found a positive gradient in the prevalence of CVD risk factors from rural Africa to urban North America (16)(17)(18) . Migration studies may therefore have the potential to increase our understanding about the increasing prevalence of overweight and obesity among these populations in Western countries.…”

Shortness at birth is associated with insulin resistance in pre-pubertal Jamaican children

“…(The Statistical Institute of Jamaica, 1996). These rates are higher than those reported for West Africa (Cooper et al, 1997). Data on the role of genetic factors in the aetiology and pathogenesis of diabetes in these populations are not available, but the gradient in prevalence across these populations of African origin is partly attributable to increasing body mass index (BMI; Cooper et al, 1997).…”

“…In Jamaica, diabetes mellitus is an important disease with a prevalence of 13.4% (Cooper et al, 1997) and it accounts for 10% of total mortality. (The Statistical Institute of Jamaica, 1996).…”