Dietary Antioxidants and Longitudinal Changes in Lower Urinary Tract Symptoms in Elderly Men: The Osteoporotic Fractures in Men Study

Association between dietary niacin intake and benign prostatic hyperplasia: a population-based results from NHANES 2003-2008

PURPOSE

Benign prostatic hyperplasia (BPH) commonly impacts the quality of life in older men. However, there is lack of research on relationship between dietary niacin intake and the risk of BPH. The purpose of this study was to investigate the relationship between dietary niacin intake and the risk of BPH.

METHODS

Data from the NHANES spanning 2003 to 2008 were utilized. BPH was determined using a self-report questionnaire, while dietary niacin intake was calculated based on the mean of two distinct diet interviews. Multivariate logistic regressions were performed to explore the association, supplemented with restricted cubic splines and subgroup analysis.

RESULTS

A total of 700 males were enrolled, of which 653 men had BPH. After adjusting for all covariates, a high dietary intake of niacin was associated with an increased risk of BPH (OR: 1.04; 95%CI: 1.01-1.07). Furthermore, when the lowest dietary niacin intake is used as the reference, the highest tertile is associated with an increased risk of BPH (OR: 2.34, 95% CI: 1.24-4,42). Restricted cubic splines demonstrated a positive correlation between dietary niacin intake and BPH risk.

CONCLUSIONS

The study results demonstrated a positive association between dietary niacin intake and the risk of BPH in elderly men in the US. These findings underscore the importance of systematic assessment before supplementing micronutrients in elderly men.

The association between several serum micronutrients and benign prostatic hyperplasia: Results from NHANES 2003-2006

BACKGROUND

Benign prostatic hyperplasia (BPH) is a common condition that affects the quality of life of older men. Specific micronutrients, including retinol, retinyl esters, carotenoids, vitamin E, and vitamin C, have antioxidant and anti-inflammatory properties. However, the correlation between serum concentrations of these micronutrients and BPH is unclear.

METHODS

We used data from the National Health and Nutrition Examination Survey (NHANES), which included 2067 representative US men. BPH was assessed using the self-reported questionnaire. This association was explored by adjusting for confounders using multivariate logistic regression.

RESULTS

After fully adjusting for confounders, for every 0.01 μmol/L increase in serum retinyl esters, the risk of BPH increased by 2% (OR = 1.02; 95% CI: 1.01-1.03; p = 0.006). Based on the Bonferroni-corrected p-value, we found this correlation to be significant. One μmol/L increase in total carotenoids was associated with a 22% increase in BPH risk (OR = 1.22; 95% CI: 1.03-1.46; p = 0.025). By analyzing the correlation between different types of carotenoids and BPH, we also found that β-carotenoids (OR = 1.43; 95% CI: 1.03-1.99; p = 0.036) was also positively correlated with BPH. The subgroup analysis revealed a positive correlation between serum vitamin E (OR = 1.02; 95% CI: 1.00-1.04; p = 0.018) and BPH in men under 60 years of age. Serum retinyl ester (OR = 1.02; 95% CI: 1.01-1.04; p = 0.008) and carotenoid (OR = 1.52; 95% CI: 1.22-1.87; p < 0.001) concentrations were positively correlated with BPH in men over 60 years of age.

CONCLUSION

Our study suggests that excessive serum retinyl esters, total carotenoids, and especially β-carotenoids are potential risk factors for BPH, and this association should be further investigated.

A Review of Oxidative Stress and Urinary Dysfunction Caused by Bladder Outlet Obstruction and Treatments Using Antioxidants

Urinary dysfunction is a common pathological condition that can significantly decrease the quality of life. Bladder outlet obstruction (BOO) is a major cause of urinary dysfunction, and various lower urinary tract diseases including benign prostatic hyperplasia and urethral stricture disease cause BOO. According to the results of a variety of animal experiments on partial BOO (PBOO), there is a general agreement that ischemic conditions and repeated ischemia/reperfusion of the bladder are closely associated with BOO-induced bladder damage, and that increased oxidative stress by ischemia/reperfusion plays a crucial role in the pathological mechanisms underlying urinary dysfunction. Changes in biomarkers of oxidative stress in PBOO animal models support this association between oxidative stress and urinary dysfunction. Oxidative stress is defined as an imbalance between the production of pro-oxidants, such as free radicals and reactive species, and their elimination through protective mechanisms of antioxidants. Therefore, organizing the knowledge on the state of oxidative stress, changes in biomarkers, and biological roles of antioxidants in systemic and bladder tissues is essential to understand the detailed pathological characteristics of the urinary dysfunction caused by PBOO. Furthermore, information on drugs and supplements that have antioxidant effects is important for defining treatment strategies for urinary dysfunction with PBOO. In this review, we paid special attention to the following three issues; (1) changes in oxidative stress, including its biomarkers, (2) antioxidant status, and (3) previous reports on treatment strategies involving agents with antioxidative activity for urinary dysfunction caused by BOO. In particular, we provide systematic information on the detailed mechanisms underlying the antioxidative effects of agents used to treat PBOO. In addition, we show present research issues and research limitations, as well as suggest possible future antioxidant treatment strategies for patients with PBOO.

What's New in Epidemiology?

There have been a number of recent advances in the epidemiological study of male lower urinary tract symptoms (LUTS). Here, we have reviewed the most novel and important literature. Studies assessing the risk factors, natural history as well as impact of male LUTS are included, focussing on recent progress in the field.