Abstract

Universally, Body Mass Index (BMI) is used to diagnose obesity, and is associated with cardiovascular disease, as well as significant morbidity and mortality.  Because the effect of obesity on health risk is influenced by ethnic background, age, and gender, using a universal BMI cut-off been questioned by some authorities or workers. Reports on appropriate BMI for Nigerians are scanty. Results of a cross-sectional study involving residents of Ado Ekiti, Nigeria, and neighboring towns and villages who participated in a health screening were analyzed. BMI cut-off which identifies the presence of hypertension and hypercholesterolemia was determined with Receiver Operating Characteristics curve. Five hundred and fifty-two (552) participants comprise of 230 (41.7%) men aged 38.8±15.6 years and 322 (58.3%) women aged 40.7±15.4 years. More women (27.7%) than men (8.8%) had obesity (p<0.001). Hypercholesterolemia was more prevalent in women (7.1%) than men (3.9%), p=0.014. Prevalence of hypertension was 24.8 and 22.0% in men and women, respectively. Overall, the prevalence of overweight/obesity and hypertension increases with age (p<0.001). The optimal BMI cut-off for men and women were 24.1kg/m² (AUC= 0.619 [95% CI, 0.535 to 0.704], p= 0.007: SS, 70.2% and SP 56.6%) and 28.9 kg/m² (AUC: 0.690 [95% CI, 0.548 to 0.831], p= 0.016: SS, 64.3% and SP 67.5%), respectively. Lower BMI cut-off than the WHO-based classification is appropriate for Nigerians. The BMI cut-off for identifying cardiovascular disease is different for men and women.

Key words: Body mass index, cardiovascular disease, obesity, cut-off, Nigeria.

Abbreviation

AUC, Area Under Curve; BMI, body mass index; CVD, cardiovascular disease; DBP, diastolic blood pressure; SBP, systolic blood pressure; ROC, receiver operating characteristic curve; WHO, World Health Organization.