The association of adiposity and overactive bladder appears to differ by gender: results from the Boston Area Community Health survey

Abstract

Purpose: We investigate the association of different measures of adiposity (waist circumference, hip circumference, waist-to-hip ratio and body mass index) with overactive bladder (urinary frequency and urgency), whether the association varies by gender or age and whether it persists when models are adjusted for other confounders.

Materials and methods: Data were from the Boston Area Community Health epidemiological survey, a random sample of 5,503 Boston, Massachusetts, residents 30 to 79 years old with equal representation from 3 racial/ethnic groups (black, Hispanic and white). Statistical analysis involved nonparametric loess models and multivariate logistic regression.

Results: We noted distinct patterns by gender for the association of various adiposity measures with overactive bladder. Waist-to-hip ratio was not significantly associated with overactive bladder in either gender. In women the prevalence of overactive bladder increased as waist (OR adjusted for other confounders 1.10/10 cm increase) or hip circumference (OR 1.12/10 cm increase) or body mass index (OR 1.03/kg/m2 increase) increased. In men the prevalence of overactive bladder decreased as adiposity increased (OR 0.65/10 cm increase in waist circumference, OR 0.71/10 cm increase in hip circumference and OR 0.87/kg/m2 in body mass index) but only to a certain point (waist circumference 100 cm, hip circumference 115 cm and body mass index 27.5 kg/m2, respectively). At that point the prevalence of overactive bladder increased with increasing adiposity (OR 1.19/10 cm increase in waist circumference, OR 1.16/10 cm increase in hip circumference and OR 1.08/kg/m2 in body mass index).

Conclusions: The relationship between adiposity and overactive bladder varies by gender.

Figure 1

Venn diagrams showing the prevalence (percent) of urinary frequency, urgency, and urge leakage by gender. The shaded area shows our definition of overactive bladder.

Figure 2

Density functions of the four adiposity measures by gender. The vertical axis is not given as it is a function of the range of the variable. The area under each curve is one.

Figure 3

Prevalence of overactive bladder by decade for men and women (left panel). Probability of overactive bladder by age for men and women using a nonparametric loess fit (right panel).

Figure 4

Probability of overactive bladder by waist circumference, hip circumference, waist-to-hip ratio, and body mass index (BMI) for men and women using a nonparametric loess fit.

Figure 5

The association of age and various adiposity measures (waist circumference, hip circumference, waist-to-hip ratio, body mass index (BMI)) with OAB for men and women using loess fits which allow an interaction between age and the adiposity measure. The curves for men are in the top row and for women in the bottom row. The curves (from the bottom) are age 30 (dark blue), age 40 (dark red), age 50 (green), age 60 (orange), age 70 (light blue), and age 80 (light red).