Serum high-sensitivity C-reactive protein concentration in healthy blood donors at the National Blood Transfusion Centre, Nairobi, Kenya

Abstract

BACKGROUND: According to the WHO, an estimated 17 million persons die annually from cardiovascular disease (CVD). The burden of CVD is rising rapidly in the developing countries but stabilizing or declining in the developed nations. This is partly due to targeting modifiable risk factors and identifying at-risk persons for close follow-up for CVD. High Sensitivity C-Reactive Protein (hsCRP) is a novel CVD risk factor, and its inclusion in global risk stratification for CVD led to reclassifying 20% - 30% of persons at intermediate risk into clinically higher or lower risk categories for f-VD. Current hsCRP risk stratification data is drawn from Caucasian populations and at the time of the study, there was no local data.

METHODS This was a cross-sectional descriptive study to determine the normative hsCRP data from 219 healthy Kenyan adult blood donors. Basic anthropometric data was obtained and the serum hsCRP level was determined using a photometric immunoturbidimetric assay method. Mean and median values were calculated and the distribution of hsCRP level was explored. We explored the effect of various exclusion criteria on the mean and median, to cater for outliers. We chose hsCRP>5mg/L exclusion criteria (n=205) to develop a normal range of values for a healthy Kenyan population. We defined a normal range as within 2.5% - 97.5% percentiles of the distribution. Bivariate and multivariate linear regression. models were used to explore the effect of gender, age. and BMI on hsCRP.

RESULTS The sample was 71 % (1SSI219) male with a median age of 26 (IQR=22-33) years. The mean BMI was 24 kg/rrr' (SD=3.8) . .. with 1 % being underweight, 68% having normal weight. 22 % overweight, 8% obese and O.S% classified as morbidly obese. The median hsCRP level was 0.6 mg/L (IQR 0.3 - 1.7mglL, Min=O.I, Max=6S.3). Excluding hsCRP >Smg/L, the median hsCRP was O.Smg/L (lQR 0.3 - 1.2 mg/L). The normal hsCRP level among Kenyan adults was calculated to lie between 0.1-3.3mglL. Bivariate and multivariate regression analysis found a significant association between hsCRP levels and gender (95% CI -0.68. 0.00 [p=0.05]), age (95%CI 0.01, 0.04 [p=O.Ol]) and BMl (9S%Cl 0.03, 0.11 [p=<O.OOl] for multivariate models). In terms of hsCRP risk categorization, 68%( 140/205) of blood donors had levels < 1 mg/L. 26% (53/20S) with 1-3 mg/L, and 6% (12/20S) with >3 mg/L.

CONCLUSION The median hsCRP in healthy Kenyan blood donors is O.S mg/L (lQR 0.3 -- 1.2 mg/L) with a normal range between 0.1 and 3.51 mg/L. Gender, age, and BMl were significantly associated the hsCRP levels. Majority of our blood donors are in the low- risk category of hsCRP stratification for CVD events. R-