Background

Observational studies among older women have associated vitamin D insufficiency with a greater prevalence and incidence of urinary incontinence. However, little is known about the effect of vitamin D supplementation in reducing urinary incontinence.

Objective

This study aimed to evaluate the effects of vitamin D supplementation in reducing the frequency of urinary incontinence in older women.

Study Design

We conducted an ancillary study of women aged ≥55 years in the Vitamin D and Omega-3 Trial, a randomized trial with a 2×2 factorial design. Recruitment of participants started from 2011 to 2014 across 50 US states, and the follow-up of participants ended in January 2018. Randomized treatments in the parent study included (1) vitamin D₃ (cholecalciferol) at a dosage of 2000 IU/d, (2) marine omega-3 fatty acids at a dosage of 1 g/d, and (3) matching placebo. Here, we analyzed women according to their randomization to vitamin D supplementation or placebo, regardless of treatment with omega-3 fatty acid supplementation. Validated frequency of urinary incontinence questions were added in year 2 of the study and were used again in year 5 at the end of trial. Prespecified ancillary outcomes included the prevalence of urinary incontinence at years 2 and 5, along with incident incontinence and progression of incontinence (from lower to higher frequency) from year 2 to year 5. Preplanned subgroup analyses examined the following outcomes: prerandomization of low serum levels of vitamin D (serum 25-hydroxyvitamin D<20 ng/mL), incontinence types, weight categories, and African American race.

Results

Among the randomized women who provided urinary incontinence data, 11,646 women at year 2 and 10,527 women at year 5, the mean age was 70 years at year 2, with 29% racial and ethnic minorities. The prevalence of urinary incontinence that occurred at least weekly was 29% at year 2 and increased to 37% at year 5. Vitamin D supplementation compared to with placebo was not associated with lower odds of urinary incontinence occurring at least weekly at year 2 (odds ratio, 1.08; 95% confidence interval, 0.99–1.19) or year 5 (odds ratio, 1.04; 95% confidence interval, 0.94–1.15). Vitamin D supplementation compared to placebo was not associated with lower incidence or progression of urinary incontinence from year 2 to year 5: incidence (odds ratio, 1.06; 95% confidence interval, 0.83–1.35) or progression (odds ratio, 0.94; 95% confidence interval, 0.82–1.08). Women with prerandomization of low serum levels of vitamin D (n=836) did not have lower odds of the prevalence, incidence, or progression of urinary incontinence. The findings were null in subgroups according to incontinence type, women with obesity, and African American women. Only women with healthy weight randomized to vitamin D had lower odds of progression of urinary incontinence (odds ratio, 0.78; 95% confidence interval, 0.63–0.95; P=.01).

Conclusion

Vitamin D supplementation compared to placebo for 2 to 5 years was not associated with differences in the prevalence, incidence, or progression of urinary incontinence in older women with and without adequate serum vitamin D levels, with inconsistent differences among subgroups. The findings showed that the broad use of moderate doses of vitamin D supplementation did not reduce urinary incontinence in older women.

中文翻译：

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补充维生素 D 对老年女性尿失禁的影响：一项随机试验的辅助发现

背景

在老年妇女中进行的观察性研究表明，维生素 D 不足与尿失禁的患病率和发病率较高有关。然而，关于补充维生素 D 对减少尿失禁的影响知之甚少。

客观的

本研究旨在评估补充维生素 D 对降低老年女性尿失禁频率的影响。

学习规划

我们在维生素 D 和 Omega-3 试验中对年龄≥55 岁的女性进行了一项辅助研究，这是一项采用 2×2 析因设计的随机试验。参与者招募于 2011 年至 2014 年在美国 50 个州开始，参与者的随访于 2018 年 1 月结束。母研究中的随机治疗包括 (1) 维生素 D ₃（胆钙化醇）剂量为 2000 IU/d，(2) 海洋 omega-3 脂肪酸剂量为 1 g/d，以及 (3) 匹配的安慰剂。在这里，我们根据女性随机分配服用维生素 D 补充剂或安慰剂对她们进行了分析，无论是否接受 omega-3 脂肪酸补充剂治疗。在研究的第 2 年添加经过验证的尿失禁频率问题，并在第 5 年试验结束时再次使用。预先指定的辅助结果包括第 2 年和第 5 年的尿失禁患病率，以及第 2 年至第 5 年的尿失禁事件和尿失禁进展（频率从低到高）。预先计划的亚组分析检查了以下结果：低血清水平的随机化前维生素 D（血清 25-羟基维生素 D<20 ng/mL）、失禁类型、体重类别、

结果

在提供尿失禁数据的随机女性中，第 2 年有 11,646 名女性，第 5 年有 10,527 名女性，第 2 年的平均年龄为 70 岁，其中 29% 为少数民族。至少每周发生一次尿失禁的患病率在第 2 年为 29%，在第 5 年增加到 37%。与安慰剂相比，补充维生素 D 与第 2 年至少每周发生一次尿失禁的几率较低无关（几率比，1.08；95% 置信区间，0.99–1.19）或第 5 年（比值比，1.04；95% 置信区间，0.94–1.15）。与安慰剂相比，补充维生素 D 与第 2 年至第 5 年较低的尿失禁发生率或进展无关：发生率（比值比，1.06；95% 置信区间，0.83–1.35）或进展（比值比，0.94；95%）置信区间，0.82–1。08). 随机化前血清维生素 D 水平较低的女性 (n=836) 的尿失禁患病率、发病率或进展几率并不低。根据失禁类型、肥胖女性和非裔美国女性，研究结果在亚组中无效。只有体重健康的女性被随机分配到维生素 D 组，尿失禁进展的几率较低（几率比，0.78；95% 置信区间，0.63–0.95；P =.01）。

结论

与安慰剂相比，补充维生素 D 2 至 5 年与血清维生素 D 水平充足和不充足的老年女性尿失禁的患病率、发病率或进展的差异无关，亚组间差异不一致。研究结果表明，广泛使用中等剂量的维生素 D 补充剂并没有减少老年女性的尿失禁。