Certain micronutrients may contribute to LUTS in women
MedWire News: Study findings show that intake of vitamin C and calcium, and β-carotene in smokers, are associated with a woman's chances of experiencing lower urinary tract symptoms (LUTS) - in particular urinary storage, or incontinence.
While moderate intake of these micronutrients could ameliorate such conditions, high doses could actually irritate the bladder, remark the researchers.
"Foods rich in vitamin C and β-cryptoxanthin have well-known health benefits that may further extend to voiding symptoms, and their consumption is encouraged," say Nancy Maserejian (New England Research Institutes, Watertown, Massachusetts, USA) and co-workers.
In light of previous, although infrequent, research indicating a possible link between oxidative stress and LUTS, the team examined associations between micronutrients with antioxidant capacity in the diet and the condition.
The cohort included 2060 women who were participants of the Boston Area Community Health (BACH) Survey and who completed a validated food frequency questionnaire, plus an at-home interview to assess factors including urologic symptoms, lifestyle, and comorbidities.
A total of 425 of the women in the analysis had moderate to severe LUTS; 8.3% had voiding symptoms, and 35.2% had storage symptoms. Among those with storage symptoms, frequency (66.1%) and nocturia (50.2%) were the most common.
Of all the micronutrients included in the analysis, no consistent associations were noted between LUTS and dietary β-carotene, lycopene, α-carotene, lutein, total carotenoids, or vitamin A.
When analysis was done per specific symptom, all individual voiding symptoms (including intermittency, hesitancy, and incomplete emptying) were inversely associated with dietary vitamin C, with hesitancy the most statistically significant symptom.
In contrast, vitamin C and β-carotene supplementation (as opposed to dietary intake) were significantly positively associated with storage symptoms. This association with β-carotene was particularly strong among smokers, who had a 3.67-fold increased risk for urinary storage symptoms (≥3000 µg/d versus nonuse), compared with former smokers and non-smokers who were a borderline significant 2.19- and 1.24-times, respectively, more likely to experience these symptoms.
When the researchers analyzed total (dietary and supplemental) vitamin C intake, they found an inverse association with voiding symptoms (akin to dietary vitamin C intake alone). Of note, high total vitamin C intake (≥400 vs <100 mg/d) correlated positively with storage symptoms such as daytime urination (odds ratio [OR]=1.88), and urgency (OR=1.87).
"Highly acidic urine, such as could result from high-dose vitamin C, plausibly could affect the urothelium and contribute to LUTS," suggest the researchers.
Total calcium intake was associated with increased risk for storage symptoms, with the most significant association observed for urinary incontinence, which increased 4.31-fold for women in the highest compared with the lowest quartiles.
This particular finding is "novel and worthy of further investigation," write Maserejian et al in the journal European Urology.
Given the noninterventional nature of BACH, additional research, including randomized trials, is needed to identify noninvasive management strategies for LUTS, they conclude.
MedWire (www.medwire-news.md) is an independent clinical news service provided by Springer Healthcare Limited. © Springer Healthcare Ltd; 2011
By Sarah Guy