The risk of obstructive sleep apnea and its association with indices of general and abdominal obesity in a Nigerian family practice clinic: a cross-sectional study

Introduction: Obstructive sleep apnea (OSA) is associated with considerable morbidity and mortality. This study assessed the prevalence of high risk of OSA and investigated which anthropometric measure best predicts the OSA risk among patients attending a family practice clinic in a tertiary hospital. Methods: We conducted a descriptive cross-sectional study of 362 consecutive patients (64% females; median age of 54 years). OSA risk was assessed by the Berlin Questionnaire and the patients were divided into two groups according to OSA risk: high and low risk. Anthropometric measurements were conducted as stated in the protocol established in the 3rd National Health and Nutrition Examination Survey. Results: Out of 362 participants, 84 [23.2% (95% CI 19.0%, 28.0%)] had high risk of OSA. Subjects with a high risk of OSA had significantly higher body mass index, waist circumference, hip circumference, and waist-to-height ratio (24.9 vs 23.8, p = 0.002; 89.0 vs 84.0, p < 0.001; 95.0 vs 91.0, p < 0.001; 0.56 vs 0.52, p < 0.001, respectively). Body mass index, waist circumference, hip circumference, and waist-to-height ratio performed similarly in predicting high risk of OSA with Area Under the Curve (AUC) of 0.661, 95% CI (0.592,0.730); 0.659, 95% CI (0.596,0.723); 0.668, 95% CI (0.604,0.733); 0.659 95% CI (0.592,0.725) respectively. The AUCs were similar when the analysis was restricted to those who were overweight. Conclusion: High risk of OSA is moderately prevalent in this population, with measures of central and abdominal adiposity equally predicting the risk

Serum reference intervals of micronutrients, vitamins, and interleukins among healthy adults in South-Western Nigeria

Objectives: Clinical decision making depends mostly on appropriate application of numerical pathology reports from laboratory results, interpreted by comparison with reference intervals. We determined serum reference intervals of micronutrients, vitamins, and detectable interleukins among healthy adults in South-Western Nigeria. Design and methods: This prospective study used a priori selection approach in blood-donors. They were screened for conditions that could elicit cytokine production.Serum micronutrients were assayed using Atomic Absorption Spectrophotometry; interleukins and vitamins by high Performance Liquid Chromatography. The reference intervals (RIs) were estimated at 2.5th percentile and 97.5th percentile. Results: One hundred and eighteen (118) apparently healthy subjects, aged 18–56 years; 113 (95.8%) being 18–44years, and 5 (4.2%): 45–56 years; mostly males, 13 (11.02%) females, all Africans of Yoruba ethnicity.Estimated reference limits were: Zinc: 9.49–20.54 μmol/L, Selenium: 0.50–1.11 μmol/L, Copper: 13.86–27.97 μmol/L, Iron: 14.19–32.07 μmol/L, Manganese: 6.24–16.37 nmol/L; Magnesium: 0.78–1.62 mmol/L.Vitamins: A-1.08–2.39 μmol/L; D: 59.89–164.42 μmol/L; E: 7.13–19.45 μmol/L; K: 0.16–0.42 nmol/L; B1: 74.09–201.56 nmol/L; B6: 0.12–0.29 nmol/L; B12: 155.55–407.96 pmol/L; C: 47.74–112.99 μmol/L.Detected interleukins (IL-1 to IL-18): IL-1: 0.58–1.24 ng/L, IL-2: 0.09–0.18 ng/L, IL-3: 0.39–0.89 ng/L, IL-4: 0.27–0.58 ng/L, ….to IL-18: 0.74–1.56 ng/L. Conclusions: The RI derived from this study for serum micronutrient, vitamin and interleukin concentrations are the first published for our population. They are in general agreement with those published from other geographical climes but there are differences at the lower and upper limits of the RI. The study reinforces the importance of deriving RI for the population that a clinical laboratory will serve