Men with androgenetic alopecia (AGA), the most common male form of hair loss and baldness, have a greater probability of developing benign prostatic hyperplasia (BPH) and metabolic syndrome, a study suggests.
The research paper, “Benign prostatic hyperplasia, metabolic syndrome and androgenic alopecia: Is there a possible relationship?“ was published in the Arab Journal of Urology.
Both AGA and BPH are disorders that display high levels of dihydrotestosterone (DHT), an androgen hormone. In the body, the enzyme 5a-reductase converts testosterone to DHT, which causes the progressive thinning and atrophy of hair follicles in the vertex, frontal and temporal areas of the scalp, resulting in hair loss (AGA), and also affects the prostate, causing BPH and urinary symptoms.
Furthermore, male baldness has been previously linked to insulin resistance (diabetes) and metabolic syndrome, a group of risk factors that increases the risk of type 2 diabetes and cardiovascular disease.
Until now, it was unclear whether these disorders were associated. The main objective of this study was to understand whether the incidence of BPH and metabolic syndrome was higher in patients with AGA compared to patients with no AGA.
The study, conducted by Dr. Naglaa F. Agamia, MD, PhD, and colleagues, included 400 men, 300 of whom had been diagnosed with AGA and 100 who did not have AGA. The patterns and severity of baldness were recorded by a dermatologist.
The patients were also analyzed in terms of weight, height, body mass index (BMI), and factors that determine the risk of metabolic syndrome, such as abdominal obesity and blood pressure, as well as levels of triglycerides, fasting blood sugar (FBS), C-reactive protein (CRP), ESR2, HbA1c (an indicator of the risk of diabetes) and levels of cholesterol in the blood.
The diagnostic criteria for BPH included prostate volume greater than 30 mL, peak urinary flow rate less than 15 mL/s, mean urinary flow rate less than 10 mL/s and PSA level of less than 10 ng/mL.
The authors observed that abdominal obesity was higher in men with AGA compared with control subjects (although there was no significant difference in weight or height), which is considered an important cardiovascular risk factor. Moreover, patients with AGA had a significantly higher risk of developing insulin resistance and type 2 diabetes.
“Both BPH and metabolic syndrome were shown to be significant independent variables associated with AGA,” the authors wrote. In fact, a significant difference in the number of patients with AGA presented diagnostic criteria of metabolic syndrome (51 percent vs 28 percent) and BPH (36 percent vs 6.8 percent), compared with the control patients.
“Dermatologists, urologists, and primary care physicians should monitor patients with early onset AGA for the development of urinary symptoms, to permit an earlier diagnosis of BPH; and for metabolic syndrome symptoms, to permit early diagnosis of cardiovascular risk factors,” the authors wrote.
The authors believe that the abdominal obesity observed in AGA patients is the common link between AGA, BPH, and metabolic syndrome, by triggering general body inflammation. In fact, several variables related to inflammation, such as values of CRP and ESR2 in the blood, were higher in patients with AGA than in control patients.
Regarding the association of inflammation with BPH, it has been observed that “the extent and severity of inflammation corresponds to the degree of prostate enlargement,” and the level of CRP is associated with higher risk of lower urinary tract symptoms (LUTS) due to BPH.
Inflammation has also been linked to insulin resistance and cardiovascular disease, and also occurs in hair follicles in patients with AGA, which further supports the idea that obesity and inflammation are powerful triggers of these three disorders.
Future studies are now needed to clarify whether treatment of AGA would also reduce BPH symptoms, and to analyze whether Avodart (dutasteride), a widely used therapy for BPH, has a protective and effective role in patients with AGA.