Serum C-reactive protein concentration and lower urinary tract symptoms in older men in the third National Health and Nutrition Examination Survey (NHANES III)

BACKGROUND. Inflammatory infiltrates are frequently found in and around nodules in benign prostate hyperplasia (BPH). We examined cross-sectionally the association of serum C-reactive protein concentration, a non-specific marker of inflammation, and lower urinary tract symptoms (LUTS), suggestive of BPH. METHODS. We included 2,337 men, 60 years and older, who participated in the Third National Health and Examination Survey (NHANES III) between 1988 and 1994. As part of NHANES III, serum C-reactive protein concentration was measured and men reported whether they currently experienced nocturia, incomplete emptying, hesitancy, or weak stream as well as whether they had had non-cancer prostate surgery in the past. All results were weighted to account for sampling probability in NHANES III. RESULTS. Age-adjusted and weighted mean serum C-reactive protein concentration was 0.32 mg/dl in men without symptoms and without surgery, 0.35 mg/dl in men with three or four symptoms (P = 0.06), and 0.36 mg/dl in men with one or two symptoms (P = 0.06). After adjusting for age and race and excluding men with an acute infection, men with a C-reactive protein concentration above the limit of detection (>0.30 mg/dl) were 1.47 times (95% CI 0.87-2.50) more likely to have three or four symptoms than men with a C-reactive protein concentration below the detection limit, although the association was not statistically significant. The association was not attenuated after adjusting for the metabolic syndrome, but was attenuated after excluding men with metabolic syndrome. CONCLUSIONS. These results suggest that elevated circulating C-reactive protein concentration might be an indicator of intraprostatic inflammation in symptomatic BPH. The presence of the metabolic syndrome might be a mediator of this association.