Background: Hepatitis C infection is associated with diabetes mellitus and insulin resistance and it is suggested that metabolic syndrome is common in patients with hepatitis C. Microalbuminuria is common in patients with diabetes and metabolic syndrome; however, no studies have examined the relationship between microalbuminuria and hepatitis C infection.
Methods: We conducted a nested case-control study to examine the relationship between nondiabetic subjects with hepatitis C infection and microalbuminuria by using the Third National Health and Nutrition Examination Survey (NHANES III) database. Study cohort consisted of 15,336 adults from the United States who had hepatitis C antibody measured as part of the NHANES III. The prevalence of microalbuminuria and the metabolic syndrome were compared between individuals with positive hepatitis C infection antibody (N= 362) and matched controls (N= 995). Additional analyses were conducted to define the association between hepatitis C infection and microalbuminuria.
Results: Prevalence of microalbuminuria in patients with hepatitis C infection was 12.4% and it was significantly higher than in controls (7.5%) (P= 0.001). This difference persisted even after excluding diabetics from the analyses (11.4% vs. 6.7%) (P= 0.001). However, there was no difference in the prevalence of the metabolic syndrome between two groups (19% vs. 19%) (P= 0.9). After controlling for relevant covariates, hepatitis C infection was independently associated with microalbuminuria in subjects without diabetes (odds ratio 1.99, 95% CI 1.38-2.85) (P= 0.008). Older age and African Americans were independently associated with microalbuminuria in nondiabetic hepatitis C patients.
Conclusion: Hepatitis C infection is independently associated with microalbuminuria but not the metabolic syndrome. Older age and African Americans are strongly associated with microalbuminuria in nondiabetic hepatitis C subjects. More research is needed to explore the implications of these observations.