Lower urinary tract symptoms (LUTS) is a recent term for what used to be known as prostatism. LUTS affects about 40% of older men. LUTS are placed into one of three categories: storage, voiding and post-micturition. Storage symptoms include increased daytime urinary frequency, getting up at night to urinate, urgency and incontinence. Voiding symptoms consist of slow stream, splitting or spraying, intermittent stream, hesitancy, straining and terminal dribble. Post-micturition symptoms involve the feeling of incomplete emptying and post-micturition dribble. The International Prostate Symptom Score (IPSS) questionnaire investigates the presence of these symptoms in seven questions, establishing the severity and quantification of LUTS.
One of most frequent conditions associated with the development of LUTS is the benign prostatic hyperplasia (BPH), a prevalent, chronic progressive hyper-proliferative condition of the prostate. BPH is one of the ten most prominent and costly diseases of men older than 50 years of age in the United States. An estimated 50% of men have histologic evidence of BPH by the age of 50 and 75% by the age of 80. BPH becomes clinically significant in about half of these men.
Dr. Nicola Caretta and colleagues, from the University of Padova in Italy, recently studied the association of 25(OH)D, LUTS and BPH in 67 men with type 2 diabetes (T2DM).
Caretta N, Vigili de Kreutzenberg S, Valente U, Guarneri G, Pizzol D, Ferlin A, Avogaro A, Foresta C. Hypovitaminosis D is associated with lower urinary tract symptoms and benign prostate hyperplasia in type 2 diabetes. Andrology. 2015 Sep 4.
The researchers used a T2DM sample because these conditions are more common in T2DM men. In a cross sectional analysis of these men, the researchers found twenty-one (31%) subjects met criteria for LUTS alone, 4 (6%) for BPH alone, 37 (55%) for both conditions and 4 (6%) experienced symptoms of neither condition. The average 25(OH)D level of the 67 men was only 14 ng/ml (35 nmol/L). Forty-five percent of the men had 25(OH)D < 10 ng/ml (25 nmol/L); 30% of the men had 25(OH)D between 10 and 20 ng/ml (25 – 50 nmol/L); while only 25% had levels above 20 ng/ml (50 nmol/L).
In their group of 67 men with T2DM, 25(OH)D levels were inversely correlated with both the International Prostate Symptom Score (IPSS) (R = 0.333; p = 0.006) and prostate volume (R = 0.311; p = 0.011). The IPSS is a screening tool used to measure and manage the symptoms of BHP.
The authors concluded:
“We demonstrate a significant association between 25-OH-vitamin D deficiency, BPH, and LUTS in T2DM men. Future studies with higher number of patients are needed to confirm our findings and to prospectively evaluate the possible influence of vitamin D treatment on the development of BPH and LUTS.”
Other studies have established similar findings. However, in this study, the R value for both BPH and LUTS is only about 0.3, meaning that 25(OH)D levels explain only 30 % of variation. That likely means that having natural vitamin D blood levels will reduce the risk of these conditions but certainly not fully prevent them.
A randomized controlled trial of vitamin D to prevent BPH and LUTS would require 20 years of treatment; for economic reasons, such a study will never be done. However, the VITAL study at Harvard of 10,000 subjects on 3,000 IU/day compared to 10,000 participants on 1,000 IU/day for 5 years may give us some answers.