Association of Androgenetic Alopecia with Benign Prostatic Hyperplasia : A Case Control Study

Introduction: Androgenetic alopecia (AGA) is associated with increased risk of several systemic diseases and some environmental factors, however, controversies exist. Since AGA and Benign Prostatic Hyperplasia (BPH) share common pathogenesis and AGA manifests some decades before BPH onset, it may serve as an early marker of BPH. Objective: This study was conducted to know AGA and its association with BPH in men ≥20 years of age. Materials and Methods: Clinically diagnosed cases of AGA (n=176) and 117 age matched healthy controls were enrolled. All cases and controls were subjected for abdomino-pelvic ultrasonography, urinary flowmetry, fasting lipid profiles, glycemic index and body mass index. International Prostate Symptom Score (IPSS) was also assessed. Results: Among 176 patients, 120 (68.18%) had Hamilton-Norwood grade III AGA and 56 (31.82%) had grade IV-VII AGA. In both groups, 140 (79.55%) cases and 93 (79.49%) controls were aged <35 years respectively. Family history of AGA was present in 108 (61.36%) cases and 2 (1.71%) controls. This observation was statistically significant with OR= 89.61 (95%CI 23.67-339.29). Three (1.7%) cases and none of the controls had prostate volume >30ml. Seventeen (9.66%) cases and 4 (3.42%) controls were graded as moderately/severely symptomatic IPSS. Statistically significant association was seen between family history and early onset of hair loss (<35 years) in a male sibling or parent. Conclusion: Although positive family history was associated with early onset of AGA, no association between AGA and BPH could be elicited in our study.


Introduction
A ndrogene c alopecia (AGA) is a hereditary disorder, mediated by androgens and characterized by progressive pa erned thinning of the scalp hair. 1 The incidence and the severity of androgene c alopecia is found to be highest in white men, second highest in Asians and African Americans, and lowest in Na ve Americans and Eskimos.Almost all pa ents have an onset by the age of 40 years, although many of the pa ents (both males and females) show evidence of AGA by the age of 30 years. 2 Although there are no serious direct health consequences, the loss of scalp hair allows ultraviolet light to reach the scalp and thus, increases risk of ac nic damage. 3AGA has been shown to be associated with increased risk of several diseases such as benign prosta c hyperplasia, 4,5 hypertension, 6 abnormal serum lipid profi les, 6 obesity, 6 insulin resistance, 7,8 cardiovascular diseases, 7 and some environmental factors such as smoking 1 and stress. 9However, controversies exist regarding the associa on of those diseases and environmental factors with AGA. 10,11censed under CC BY 4.0 International License which permits use, distribution and reproduction in any medium, provided the original work is properly cited.http://dx.doi.org/10.3126/njdvl.v16i1.19399NJDVL.Vol 16, No. 1, 2018   Benign prosta c hyperplasia (BPH) is the commonest benign neoplasm in men aged 70 years and older with or without obstruc ve symptoms aff ec ng more than 70% of men. 4 BPH is more common among elderly men but infrequent in age less than 40 years.Its prevalence increases above the age of 60 years.Androgen func on and pa ents' age are important for the occurrence of BPH. 5 Since AGA and BPH share common pathogenesis and AGA manifests some decades before BPH onset, it may serve as an early marker of BPH.

Materials and Methods
The study was conducted in the outpa ent department (OPD) of dermatology, BP Koirala Ins tute of Health Sciences, Dharan between 1st April 2013 and 31st March 2014.All clinically diagnosed cases of AGA (n=176) and 117 age matched healthy controls were enrolled between 1 st April 2013 and 31st March 2014 in our study with prior informed and wri en consent.Ethical clearance was taken from the ins tu onal ethical commi ee.Detail history about the disease, family history of AGA or BPH, personal history of cardiovascular disease, hypertension, diabetes mellitus, alcoholism, cigare e smoking, lifestyle, drug intake was recorded in a preset proforma.Data regarding age, weight, height, waist circumference, body mass index, IPSS score were recorded.All cases and controls were subjected for abdomino-pelvic ultrasonography, urinary fl owmetry, fas ng lipid profi les and glycemic index measurement.The severity of baldness was also es mated from photographs taken at an anterior view, 900 lt to the front side of the head, right and le 900 side views.
Sta s cal analyses were done using with So ware SPSS (version 10.0 for Windows, SPSS Inc, Chicago, IL).The baseline characteris cs of the study pa ents were expressed as numbers and percentages for categorical variables and as mean±standard devia on for con nuous variables.Qualita ve variables were analyzed using χ2 test or the Fischer's exact test.A logis c regression model was employed to assess the associa ons between each possible risk factor (BPH, smoking, Body Mass Index, waist circumference, fas ng plasma glucose, Blood Pressure (BP), and serum level of lipids, including Triglyceride (TG) and High Density Lipoprotein (HDL) and the risk of developing AGA (type III or greater).The sta s cal signifi cance level was set at 5% for assessing each associa on, odds ra o (ORs) and their 95% confi dence intervals (CIs).The odds ra o was determined by the Wald Chi-square test, and predictors with p<0.10 were subsequently assessed using mul variate analyses with a forward stepwise selec on procedure.The threshold of 0.05 was regarded as signifi cant with the logis c model of regression.

Results
Total of 176 cases and 117 controls were analyzed in this study.The mean±SD age of case and control groups were 29.40±8.74years and 29.62±9.47years, respec vely.
In this study, 68.18% of popula on had Grade III AGA, followed by Grade IV (21.02%).Majority of the popula on in the study followed Hindu religion in both the case and control groups (92.61% vs. 89.55%)respec vely.Sixty-three (35.8%) cases and 48 (41.02%) controls were married, and most of the popula on belonged to middle class family (Table 1).Emo onal stress was found to be the commonest precipita ng factor (66.7%) in the cases.In this study, 100 (56.8%) cases and 53 (45.29%) controls lived non-sedentary life style.
Family history of AGA was present in 108 (61.36%) pa ents and two controls (1.7%).This was found to be sta s cally signifi cant (OR=89.61;95% CI 23.67-339.29 and p value <0.001).First degree rela ves of the pa ents had a posi ve family history of AGA in 44.8%.Site of onset of AGA was frontal in 78.4% of the cases.Three (1.7%) of the cases had prostate volume >30ml and none of the pa ents in control group had prostate volume >30ml.Seventeen (9.66%) pa ents and four (3.42%) controls were graded as moderately/ severely symptoma c IPSS.In univariate analysis, there was no signifi cant associa on found between the AGA and BPH, age <35years, family history of BPH, past treatment taken for other diseases, blood pressure, blood sugar level, prostate specifi c an gen, cigare e smoking, cholesterol, triglyceride, Low Density Lipoprotein (LDL) and HDL level.The family history of AGA and IPSS were signifi cantly associated in cases as compared to controls and conversely BMI and Waist circumference was sta s cally signifi cant in control group as compared to cases (Table 1).But in mul variate analysis, only family history of AGA was signifi cantly associated with androgene c alopecia in our study (Table 4).

Discussion
Androgene c alopecia (AGA) is associated with increased risk of several systemic diseases and some environmental factors, however, controversies exist.Androgens like Testosterone and Dihydrotestosterone are involved in diseases like AGA and BPH.The enzyme 5-alpha reductase, which transforms testosterone into DHT, plays a key role.In pa ents with AGA, scalp biopsy specimens have shown increased DHT concentra ons and 5-alpha-reductase ac vity. 12,13 a study done by Oh et al 14 , BPH had strong associa on with higher grade of male pa ern baldness than that of controls (median value of grade IV versus III, p value <0.001).Similarly, Arias-San ago S et al in an observa onal case-control study found strong associa on between the presence of AGA and benign prosta c hyperplasia with odds ra o of 5.14. 5 Male pa ern baldness is an androgen dependent disorder in adult men.Though the pathogenesis is not well understood, it is believed that the androgens act on the hair follicle via the mesenchyme-derived dermal papilla present in the middle of the hair follicle bulb. 15The pa ents having autosomal recessive gene c disorder of 5 α-reductase defi ciency do not develop Androgene c Alopecia, which suggests that DHT is the androgen responsible for it. 16Dihydrotestosterone, an androgen controls the normal growth and secretory func ons of the prostate gland, thus maintains Benign Prosta c hyperplasia (BPH).
The prevalence of AGA increases steadily with advancing age.High prevalence has been found among men of white race/ethnicity, whereas lower prevalence has been seen among Asians, Na ve American, and African American men.Increased risk of AGA with age refl ects the natural progression of this condi on. 17 AGA gradual thinning in the temporal areas are present, producing a reshaping of the anterior hairline. 18By the age of 20 years, more than 90% of men demonstrate some degree of fronto-parietal recession of hairline. 19Among our study popula on, 138 (78.4%) pa ents had frontal region involvement followed by vertex involvement observed in 53 (30.1%) pa ents of AGA.Rate of progression is infl uenced by gene c predisposi on. 20 our study, out of total 34 pa ents having precipita ng factor for androgene c alopecia, emo onal stress was the major precipita ng factor found in 20 (66.7%) pa ents.Stress responses, mediated by typical stress hormones, like catecholamines, prolac n, Adrenoco cotrophic hormone (ACTH), Cor cotrophin Releasing Hormone (CRH), b-endorphins, glucocor coids, and substance P directly and indirectly alter hair growth by interac ng and disturbing the release of the various neuropep des. 9 The gene c inheritance of AGA has been documented well in the literature, but only few studies have been done regarding familial aggrega on of AGA.Also, one gene that encodes for androgen receptor in gene polymorphism of AGA has been iden fi ed. 17Our study also reports that male rela ves were more prone to have AGA if there were young family members with AGA.
The various diseases associated with AGA are benign prosta c hyperplasia, 4,5 hypertension, 6 obesity, 6 dyslipidemia, 6 insulin resistance 7,8 and cardiovascular diseases. 7In our study, three pa ents (1.7%) in case group had diabetes mellitus.This fi nding is in corrobora on with two studies Ma lainen VA et al 7 and González-González JG et al 8 that showed associa on of diabetes mellitus due to insulin resistance in AGA.
Similarly, 3 (1.7%)3][14] Only 1 (0.56%) pa ent had hypertension.Associa on between AGA and hypertension has been shown in several previous studies. 6,7,10,21  diff erence in the blood pressure might be due to the androgens binding to mineralocor coid receptors, which may be responsible for development of hypertension in men as compared to women. 22lso hyperaldosteronism which has been found to be causa ve factor for primary hypertension in literature, may directly lead to the development of alopecia. 21n our study, only one (0.6%) pa ent had Systolic BP ≥140 mm Hg and fi ve cases (2.8%) had Diastolic BP ≥90 mm Hg.This fi nding is in contrast to the study done by Ahouansou S et al who found strong associa on between Androgene c alopecia and hypertension. 21he majority of younger popula on in our study could explain this fi nding.
Berry SJ et al reported that 50% of men develop BPH by the sixth decade of life, which rises to 70% and 90% by the seventh and ninth decade respec vely. 23With increase in literacy, general awareness of prosta c disease will increase leading to rise in the number of BPH pa ents.Boyle P reported that by the end of the century, men popula on are expected to have an 88% chance of developing BPH and above 50% chance of developing symptoms, and thus male pa ern baldness. 24In our study only 1.7% of the cases had BPH, among them two had grade III and one had grade IV male pa ern baldness.This may be because pa ents with AGA were of younger age than in other studies. 23,24 is evident from the previous studies that the volume of prostate increases with increasing age and common a er 4 th decade of life, 23,24 which is comparable with our study as mean prostate size was found to be greater in case group (11.15 cm 3 ) as compared to control group (6.24 cm 3 ).This is in corrobora on with the study done by Chen W et al, who found high prevalence of alopecia in pa ents with more than 30 cm 3 prostate size as compared to smaller prostate (83.3% vs. 61.3%,p value <0.05). 11In this study prostate size was mildly larger, but not signifi cantly higher in AGA pa ents in comparison to the controls (42.7 vs. 35.4cm 3 ) and it did not diff er with grading of alopecia (Norwood-Hamilton scale).
In our study, 17 pa ents (9.7%) in case group and four pa ents (3.4%) in control group were moderately/ severely symptoma c.Though result was signifi cant in bivariate analysis with p value= 0.042 (CI: 0.98-9.21),NJDVL.Vol 16, No.1, 2018 but it was not sta s cally signifi cant in mul variate analysis.
It is in corrobora on with the study done by Arias-San ago S et al in which AGA pa ents with larger prostate volume had early change in urinary fl ow and higher IPSS. 5 Cigare e smoking causes damage to the vascular supply of the dermal hair papilla and also to the DNA of the hair follicles.Smoking also causes proinfl ammatory cytokines release due to oxida ve stress resul ng in follicular microinfl amma on and fi brosis.Cigare e smoking can lead to an protease system imbalance and also hypoestrogenic state. 1 In our study, we found that AGA was not associated with cigare e smoking as 62.5% of the cases were non-smokers, 12.5% had either quit smoking and 25% were current smokers.

Conclusion
We can conclude that posi ve family history of the androgene c alopecia increases the chances of developing androgene c alopecia in men though with increasing age.No associa on between androgene c alopecia and benign prosta c alopecia could be elicited from our study.But majority of pa ents in our study were of younger age group and BPH is not a common fi nding of younger age group.Further mul center studies with a larger sample size to evaluate the associa on of Benign prosta c hyperplasia (BPH) and other risk factors with androgene c alopecia (AGA) is recommended.

Table 1 .
Clinical and laboratory parameters associated with Androgene c Alopecia *Fischer's exact test

Table 2 :
Comparison of prostate volume in two groups.

Table 3 :
Comparison of diff erent variables among the type of AGA.

Table 4 :
Mul variate logis c regression analysis for AGA.