Objective: To examine the relationship of serum magnesium and high-sensitive C-reactive proteins (hsCRPs) with overweight/obesity, and its association with hypertension in lean versus overweight/obese (O/O), female, adolescent school learners living in Mthatha, Eastern Cape, South Africa.
Methods: A case-control study was conducted involving age-matched, non-pregnant and nonlactating lean and O/O females aged 13–17 years. Relevant data on demography, anthropometry (height, weight, and waist and hip circumferences), blood pressure and venous blood samples were collected.
Results: A significant inverse correlation was observed between serum magnesium and waist circumference (WC) (r = −0.3153; 95% CI = −3.843, −0.8681; p = 0.0022). Serum hsCRP levels were significantly higher in O/O participants. Participants with a WC > 80 cm had significantly higher mean systolic blood pressure and mean diastolic blood pressure (MDBP). A hip circumference (HC) > 94 cm was associated with higher mean systolic blood pressure (MSBP) and MDBP (120 ± 2 vs 113 ± 2, p = 0.009 and 73 ± 2 vs 68 ± 1, p = 0.003). Both WC and HC were found to be positively correlated with both MSBP (r = 0.2691; 95% CI = 0.042, 0.457; p = 0.018 and r = 0.2758; 95% CI = 0.03184, 0.3001; p = 0.0159) and MDBP (r = 0.2686; 95% CI = 0.0286, 0.320; p = 0.19 and r = 0.2836; 95% CI = 0.05382, 0.4455; p = 0.013), respectively.
Conclusion: In our study, low-grade inflammation and early-onset hypertension in O/O adolescent females were consistent with evidence that support the beneficial effect of maintaining lean body habitus. There is an urgent need to prevent overweight/obesity among adolescents.