Studies conducted in Asia demonstrated an association between metabolic syndrome and lower urinary tract symptoms (LUTS) or benign prostatic hyperplasia (BPH), according to a presentation at the 14th Urological Association of Asia (UAA) Congress 2016 held in Singapore.
A recent meta-analysis conducted in China showed that BPH patients with metabolic syndrome had a significantly higher total prostate volume (pooled mean difference [WMD], 10.15 ml, 95 percent confidence interval [CI], 7.37-12.93) and serum prostate-specific antigen (PSA) levels (WMD, 0.53 ng/ml, 95 percent CI, 0.17-0.88) than BPH patients without metabolic syndrome. Patients with metabolic syndrome also had a higher annual prostate growth rate (WMD, 0.49 ml/year, 95 percent CI, 0.24-0.73). [World J Urol 2016;34:281-289]
A small study in Turkey also demonstrated an increased incidence of metabolic syndrome alongside the increase in symptom severity in patients with BPH-related LUTS. [Turk J Urol 2015;41:7-12]
In contrast with these findings, a Japanese study involving 900 patients found no association between metabolic syndrome and LUTS, [Urology 2011;77:1432-1438] while a Taiwanese study (n=708) found that metabolic syndrome had “favourable effects” on LUTS, with the beneficial effects most prominent in men with higher PSA levels or an enlarged prostate. [Urology 2012;80:1093-1097]
According to Dr. Peggy Chu from the Division of Urology at Tuen Mun Hospital, Hong Kong who presented the findings, the first prospective study examining the relationship between prostate volume and individual metabolic syndrome components in men with BPH found that non-insulin-dependent diabetes mellitus, treated hypertension, obesity, high fasting insulin levels, and low HDL cholesterol levels were risk factors for prostate enlargement. [Prostate Cancer Prostatic Dis 1998;1:157-162]
Several other international studies have demonstrated an association between metabolic syndrome and BPH. One study showed that men who were obese or dyslipidaemic had an increased risk of metabolic syndrome being a determinant of their prostate enlargement. [BJU Int 2015;115:24-31] Another study showed an association between metabolic syndrome and higher prostatic volume, prostate symptom score, and voiding symptoms but not maximum urine flow rate (Qmax) or PSA levels. [Asian J Androl 2015;17:826-830]
A study involving the third National Health and Nutrition Examination Survey (NHANES III) participants also found an association between a history of diabetes or hypertension and LUTS. [Int J Obes (Lond)2005;29:310-316]
In a recent large, cross-sectional epidemiological study conducted in the UK involving men age ≥50 years, researchers found that compared to individuals without BPH, those with BPH had a higher incidence of metabolic syndrome (20.9 vs 26.5 percent; p<0.001). [BJU Int 2016;117:801-808]
A meta-analysis involving 5,403 participants (26.4 percent had metabolic syndrome; n=1,426) found that men with metabolic syndrome had a significantly higher total prostate volume compared to those without metabolic syndrome (+1.8 ml, 95 percent CI, 0.74-2.87; p<0.001). The differences in total prostate volume were also higher in obese patients (p<0.005) and those with low HDL cholesterol levels (p<0.001). [BJU Int 2015;115:24-31]
“An estimated 45.2 and 21.5 percent of the 2008 worldwide population was affected by at least one LUTS and LUTS/BOO [LUTS suggestive of bladder outlet obstruction], respectively. The regional burden is estimated to be greatest in Asia,” said Chu, who recommended that further studies be carried out with long-term results to better understand the natural history of metabolic syndrome in men with LUTS.