Systematic review on the prevalence of diabetes, overweight/obesity and physical inactivity in Ghanaians and Nigerians

Summary Objective To review the prevalence of diabetes, obesity and physical inactivity among Ghanaians and Nigerians in Africa, Europe and North America. Methods This systematic literature review used MEDLINE 1966–2005, EMBASE 1980–2005 and cited references to identify relevant studies on Ghanaians and Nigerians. Results No studies on Ghanaians or Nigerians in Europe or North America have been reported. Sixteen studies in Africa were included; 13 on Nigerians and three on Ghanaians. The data were limited, poorly reported and not easily comparable. Pooled analysis was not possible. Precise time trend analysis was not possible, but diabetes seemed rare at 0.2% in urban Ghana in 1963 and 1.65% in urban Nigeria in 1985. The prevalence of diabetes in Nigerian adults (age ⩾40 years) in 2000 was 6.8% [confidence intervals (CI) 4.6–9.0]. In Ghana, the prevalence of diabetes in adults (age ⩾25 years) was 6.3% (CI 5.6–7.0) in 1998. Obesity (body mass index ⩾30) among Nigerian adults was 8.8% (CI 7.0–10.6) in 2000, and obesity in Ghanaian adults (⩾25 years) was 14.1% (CI 13.1–15.1%) in 1998. Various studies reported that 25–57% of Nigerians were physically inactive. Conclusion Although weak, the evidence base points to a rise in diabetes prevalence in Ghana and Nigeria, with major urban–rural differences. There is an urgent need for accurate and comparable surveys on diabetes and its risk factors among Nigerians and Ghanaians. Effective public health policies are vital to control the diabetes epidemic.