Need for Age-Specific Prostate-Specific Antigen Reference Intervals in a Nigerian Population

Abstract

ABSTRACT Background: In Nigeria, the diagnostic value of prostate-specific antigen (PSA) is a matter of debate. PSA levels are known to vary with population, environmental factors, and advancing age. Studies suggest age-specific reference intervals (ASRIs) of PSA value are more accurate than single cut-off PSA value. For ASRIs to be used effectively, reference intervals (RIs) must be fully evaluated. Aim: We determine ASRIs in a Nigerian population. Materials and Methods: The study was carried out from January 2016 to January 2019 among 660 adult Nigerian men aged 30–86 years old in Enugu State. Participants completed questionnaire demographics and previous screening. Age group was the indicator. Among them, a total 24 (3.6%) were excluded. Data from 636 (96.4%) men were analyzed for ASRIs. Estimation of PSA was done as per the International Federation of Clinical Chemistry Guideline. Spearman correlation was used to identify correlates P values < 0.05 which was considered significant. Results: The mean age group was 49.6 ± 10.2 years. ASRIs using 95th percentile, and PSA values in each 10 years groups were 0–1.94 ng/ml (median 0.22), 0–2.52 ng/ml (median 0.42), 0–3.52 ng/ml (median 1.06), 0–4.8 ng/ml (median 2.1), 0–6.95 ng/ml (median 4.1), and 0–5.6 ng/ml (median 2.4), for age groups 30–39, 40–49, 50–59, 60–69, 70–79, and ≥80 years, respectively. There was positive correlation between PSA and age (r = 0.9915, P < 0.0001). Low income and educational background were more prevalent among the study group. Conclusion: Our study provided the ASRIs in our environment but higher than single cut-off value. The data recommended PSA values should be characterized by age and ethnicity.