Reference intervals for common biochemical analytes in serum and plasma of a random adult population in the Greater Accra Region of Ghana

Background: The reference interval (RI) is arguably the most widely used decision making tool in clinical practice. Using the manufacturer's reference values may not be appropriate for other ethnic populations. Objective: The objective was to determine the reference intervals (RI) of Ghanaians and compare them to that provided in kits. Methods: 6300 adults, 25-65 years were selected by cluster sampling from three communities in the Greater Accra Region, Ghana. A total of 4733 (male/female ratio = 1:1.5) participated. Fasting Blood Glucose (FF), 2-hour post-glucose plasma glucose (2HPP), total cholesterol (TCHOL), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), triglycerides (TG), uric acid (UA), urea (U), albumin (ALB), alkaline phosphatase (ALP) were measured. Results: Male and female mean ages were 44.9 ±14.7 and 44.0 ±14.6 years, respectively. Most assays had mean values between the 25th and 75th percentile apart from HDL-C whose mean values fell within the 50th percentile. Thus half of the manufacturers RI (MRI) represented <25 percentile for FF, 2HPP, LDL-C, ALB and ALP. The MRI for Urea was <25th - >97.5th. Conclusions: Mean values of most of the parameters determined represented the 25th-75th and not the 95th or 97.5th percentile.