Background: Estimates of the prevalence of paraproteinaemia vary, from 1% in persons aged over 25 years to 10% in those aged over 80 years, although there are limited data from well-defined populations. We sought to determine the prevalence of paraproteinaemia in Australians aged 50 years and over, and to determine risks factors for its presence.
Methods: We performed a population-based, cross-sectional study using data and serum collected in the Blue Mountains Eye Study. Serum samples from 2933 patients were analysed by capillary zone electrophoresis and, where indicated, immunosubtraction, which allowed for both quantitation and isotype detection.
Results: A paraprotein was detected in 134 of the 2933 samples, giving an overall prevalence of 4.6% (95% confidence interval, 3.8–5.3%). The presence of a paraprotein was strongly age-related (Ptrend= 0.001), with a prevalence of 2.8% in persons aged 50–59 years, rising steadily to 9.1% in those aged 80 years and over. The prevalence was significantly higher in men (5.9%) compared with women (4.0%) (P= 0.03).
Conclusion: We conclude that approximately one in 20 Australians aged 50 years or over harbours a paraprotein, a prevalence that appears higher than from similar cohorts in other countries.