Burden of Dyslipidemia and Metabolic Syndrome among Indigenous Black African Secondary School Students in Lagos, Nigeria

Abstract

_Introduction:_ Metabolic syndrome (MetS) is a group of risk factors which together increase the chance of heart disease, stroke, and type 2 diabetes. In MetS, especially among overweight and obese people, blood pressure and blood glucose are elevated, excess body fat accumulates abdominally, and there is dyslipidemia – notably low level of high-density lipoprotein (HDL) cholesterol and high level of triglycerides. _OBJECTIVES: _This study has three objectives: (i) determine the prevalence of dysglycemia and of dyslipidaemia among Nigerian adolescents relative to gender (boys and girls), stage of adolescence (early and late) and BMI-for-age percentile (lean and overweight/obese) (ii) to quantify the burden of lipid abnormalities (excessive Total cholesterol (TC), Triglyceride (TG), High-density lipoprotein cholesterol (HDL) and Low-density lipoprotein (LDL) cholesterol) among Nigerian adolescents, which have appeared as substantial covariates of coronary heart disease (CHD) and (iii).To evaluate the association of overweight/obesity, dysglycemia and dyslipidaemia with MetS at (≥90th percentile). _POPULATION AND METHODS: _An institution-based, cross-sectional, descriptive, epidemiological study was conducted from October 2019 to March 2020. A multi-stage sampling approach was used to recruit 650 students aged 10-19 years in secondary schools within Lagos State of Nigeria. Data were collected using a structured questionnaire and anthropometric measurements. Fasting venous blood samples were collected for plasma glucose and lipid profile analysis. Systolic and diastolic blood pressures were measured. A p-value <0.05 was taken as statistically significant. Twenty-six questionnaires were discarded due to incomplete data. _RESULTS:_ A total of 650 adolescents aged between 10 and 19 years were included but 624 were analyzed with 26 discarded due to incomplete data. The overall means (±sd) of age was 14.7±2.2 yrs. with no significant difference between boys (14.8±2.2) yrs. and girls (14.7±2.1 yrs.). Girls were significantly heavier (t-test=-2.24, P-value=0.03) than boys (19.5±4.1 vs 18.7±4.5 kg/m2). The overall prevalence of hyperglycemia was 11.7%. The mean Systolic blood pressure (SBP) of overweight/obese subjects (113.6±11.9 mm Hg) was significantly higher (t-test=-8.81, P-value<0.00001) than that of lean subjects. Approximately 19% and 12% of the study subjects had impaired and diabetic fasting blood glucose (FBG), especially females, those in early-stage adolescence and the overweight subjects. The median lipid levels were 199.4 mg/dL for TC, 180.8 mg/dL for TG, 55.9 mg/dL for HDL and 289.6 mg/dL for LDL respectively. Only 53 (8.3%) subjects had abnormal levels of combined TC, TG, HDL, and LDL. Boys were 1.59 more likely to have dyslipidemia compared to girls (χ²=2.66, P-value=0.10, Or=1.59, 95% CI=0.92, 2.76) and overweight/obese subjects were 1.53 more likely to develop dyslipidemia compared to lean subjects (χ²=0.86, P-value=0.35, OR=1.53, 95% CI=0.62, 3.77). Overweight with dyslipidemia were significantly younger (t-test=2.54, P-value=0.04). The overall prevalence of metabolic syndrome (MetS) was 8.3% with roughly 15%, 44%, 32% and 9% of the study subjects having 0, 1, 2 or ≥3 risk factors for MetS. _CONCLUSION: _A higher proportion of male, mid-adolescent, and overweight students had a minimum of 3 risk factors for MetS_. _This is likely to impose a high burden on future health. Preventing the increasing burden of lipid abnormalities among Nigerian adolescents is essential. The extent to which the problem might affect other areas of Nigeria needs investigation. Multivariate regression analysis shows that the overall relationship between MetS ≥90th percentile and five predictor variables – FBG, TC, TG, HDL, and BMI-for-age, was significant (P-VALUE<0.00001) and all of them contributed to the observed MetS≥90th percentile among the study subjects.