Lower urinary tract symptoms (LUTS) are highly prevalent in the adult population with the most prominent symptom being overactive bladder (OAB) syndrome. To date, there are no epidemiologic studies that focus on the prevalence of LUTS for Asian Americans or their subgroups in the US. Despite the fact that Asian Americans comprise 5.6% of the US population, Asian Americans have been largely underrepresented in lower urinary tract research. Of the numerous Asian American subgroups, Chinese Americans constitute the largest subgroup of all. In order to bridge the gap of knowledge in LUTS among Asian Americans, this is the first study that aims to describe LUTS prevalence, whether or not there are gender differences in LUTS prevalence, and risk factors associated with LUTS in a community-dwelling elderly Chinese American population.

We performed a secondary analysis of a prospective cross-sectional population-based survey of Chinese Americans aged 60 and older living in the Chicago area between the years 2011-2013. These surveys were conducted in English or one of the Chinese dialects, including Mandarin, Cantonese, Taishanese, or Teochew. A clinical review of system (ROS) was used to assess LUTS, which included frequency, urgency, burning or pain, blood in urine, and incontinence. Within LUTS, a subgroup of overactive bladder without incontinence (OAB-dry) was defined as urgency and/or frequency without incontinence. Descriptive statistics for demographics, risk factors, and individual general health perceptions were performed using students t-test and chi-square where appropriate. Multivariable logistic regression was used to identify independent risk factors.

Of the total 3,157 people queried, 1,328 (42%) were men and 1,829 (58%) were women. The mean(±SD) age was 72.8±8.3 years and 30.4% reported of at least one LUTS. There was a higher proportion of men who reported LUTS when compared to women (32.9% vs 28.7%, p=0.01). Of the individual LUTS, 27.9% of men reported frequency, 16.5% with urgency, 2.9% with burning/pain, 1.5% with hematuria, and 2.9% with incontinence. In women, 22.4% reported frequency, 12.6% with urgency, 2.2% with burning/pain, 1.7% with hematuria, and 5.6% with incontinence. When organizing these individual LUTS to meet the definition for OAB-dry, more men met the OAB-dry symptom criteria than women (28.8% vs 21.2%, p<0.0001). When compared to men with any LUTS, women with any LUTS had significantly lower rates of smoking, alcohol use, and heart disease but higher rates of frequent traditional Chinese medicine (monthly or more TCM) use, cognitive impairment, and difficulties with physical functions and activities of daily living (Table 1). Women with LUTS also had a poorer general health perception than men with LUTS (p=0.01).

In a multivariable analysis evaluating the overall population with any LUTS (Table 2), female gender (aOR 0.60, 95%CI 0.49-0.73), being married (aOR 0.79, 95%CI 0.65-0.97), and smoking (aOR 0.66, 95%CI 0.49-0.88) were found to be protective; while frequent TCM use (aOR 1.51, 95% CI 1.28-1.78), heart disease (aOR 1.54, 95%CI 1.24-1.91), and anxiety (aOR 1.69, 95%CI 1.25-2.28) were most strongly associated with increased odds of reporting any LUTS. When applying the same multivariable regression to the total population with OAB-dry, female gender (aOR 0.52, 95%CI 0.42-0.63) and smoking (aOR 0.67, 95%CI 0.49-0.90) were again found to be protective while frequent TCM use (aOR 1.51, 95%CI 1.26-1.80), heart disease (aOR 1.47, 95%CI 1.18-1.84), and anxiety (aOR 1.47, 95%CI 1.08-2.01) were also found to be most associated with increased odds of reporting OAB-dry symptom as observed in LUTS. 

When examining men and women separately using the same multivariable regression model, being married was found to be protective only for women with LUTS (aOR 0.75, 95%CI 0.59-0.96), but not for men. Depression was also strongly associated with LUTS in women (aOR 1.70, 95%CI 1.28-2.26) while anxiety was associated with LUTS in men (aOR 2.74, 95%CI 1.54-4.87). Frequent TCM use was the only factor that was significantly associated with an increased odds of LUTS in both men and women. Other gender-specific factors that were associated with an increased odds of LUTS in men but not women included hypertension, heart disease, and practice of Taichi. When analyzing the OAB-dry subgroup, most associations were similar to those found in LUTS; however, smoking was found to be protective (aOR 0.72, 95%CI 0.52-0.99) in men with OAB-dry only.

In this large population-based study, LUTS were more prevalent in elderly Chinese American men than women. We also found gender-specific factors that influenced the odds of reporting any LUTS; however, frequent TCM use was the only shared characteristic between both genders reporting any LUTS. Of all the LUTS, OAB-dry was the most commonly reported symptom. OAB-dry subgroup shared similar associations as those for LUTS in general. Lastly, comparing between men and women with any LUTS, women with any LUTS were more likely to have lower baseline cognitive and physical functions than men.

This is the first study to specifically address LUTS in community-dwelling elderly Chinese Americans. Gender-specific differences were noted in factors associated with LUTS and OAB-dry. This study highlights the unique risk factors for elderly Chinese American men and women with LUTS and underscores the importance of expanding lower urinary tract research to incorporate greater diversity in its study populations. In addition, more longitudinal investigations are needed to elucidate the underlying mechanisms of LUTS to provide evidence-based and culturally specific clinical guidelines for the rapidly growing Chinese American population in the US.