Sex hormone-binding globulin and risk of hyperglycemia in patients with androgenetic alopecia
ABSTRACT Low circulating levels of sex hormone-binding globulin (SHBG) are a strong predictor of the risk of type 2 diabetes. Androgenetic alopecia (AGA) has been related to an increase in cardiovascular risk, but the mechanism of this association has not been elucidated. AGA can be associated with low levels of SHBG and insulin resistance, which could be related to hyperglycemia and type 2 diabetes.
The objective of this study was to evaluate SHBG and blood glucose levels in men and women with early-onset AGA and control subjects to determine whether low levels of SHBG are associated with hyperglycemia.
This case-control study included 240 patients consecutively admitted to the outpatient clinic (Dermatology Department of San Cecilio University Hospital, Granada, Spain), 120 with early-onset AGA (60 men and 60 women) and 120 control subjects (60 men and 60 women) with skin diseases other than alopecia.
Of patients with AGA, 39.1% presented with hyperglycemia (>110 mg/dL) versus 12.5% of controls (P < 0.0001). AGA patients with hyperglycemia or diabetes presented lower significant levels of SHBG than alopecic patients without hyperglycemia or type 2 diabetes, respectively. Patients with AGA and hyperglycemia presented significantly lower levels of SHBG than controls with hyperglycemia (22.3 vs 39.4 nmol/L for AGA patients and controls, respectively, P = .004). No significant differences in SHBG levels were noticed between patients and controls without hyperglycemia. Binary logistic regression showed a strong association between lower SHBG levels and glucose levels greater than 110 mg/dL in patients with AGA even after additional adjustment for sex, abdominal obesity, and free testosterone (odds ratio = 3.35; 95% confidence interval = 1.9-5.7; P < .001).
The study of a wider sample of AGA patients would confirm these findings and would permit analysis of the pathogenic mechanisms underlying the increase in cardiovascular risk in patients with AGA.
An association between early-onset AGA, hyperglycemia/diabetes, and low levels of SHBG was observed in the current study. Low levels of SHBG could be a marker of insulin resistance and hyperglycemia/diabetes in patients with AGA.
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ABSTRACT: Androgenetic alopecia (AGA) and benign prostatic hyperplasia are both androgen-dependent entities that respond to the blocking of 5-alpha-reductase. The objective of this study was to determine whether prostatic volumes and urinary flow changes were higher in patients with early-onset AGA than in healthy control subjects. This was an observational case-control study of 87 men: 45 with early-onset AGA diagnosed in the dermatology department and 42 control subjects. End-point variables were prostatic volume, measured by transrectal ultrasound, and urinary flow, measured by urinary flowmetry. A hormone study was performed on all participants, and the International Prostate Symptom Score and International Index of Erectile Function score were determined. The groups did not significantly differ in mean age (cases, 52.7 years vs control subjects, 49.8 years; P = .12). Patients with AGA had significantly higher mean prostate volume (29.65 vs 20.24 mL, P < .0001), International Prostate Symptom Score (4.93 vs 1.23, P < .0001), and prostate-specific antigen value (1.53 vs 0.94 ng/mL, P < .0001) and significantly lower maximum urinary flow (14.5 vs 22.45 mL/s, P < .0001) versus control subjects. Binary logistic regression analysis showed a strong association between the presence of AGA and benign prostatic hyperplasia after adjusting for age, urinary volume, urination time, International Prostate Symptom Score, abdominal obesity, glucose levels, systolic blood pressure, insulin levels, fibrinogen, and C-reactive protein (odds ratio = 5.14, 95% confidence interval 1.23-47.36, P = .041). The study of larger sample sizes would facilitate stratified analyses according to the Ebling type of androgenetic alopecia. There is a relationship between the presence of AGA and prostate growth-associated urinary symptoms, likely attributable to their pathophysiological similarity. This study suggests that early-onset AGA may be an early marker of urinary/prostatic symptomatology. Future studies may clarify whether treatment of patients with AGA may benefit the concomitant benign prostatic hypertrophy, which would be present at an earlier stage in its natural evolution.Journal of the American Academy of Dermatology 08/2011; 66(3):401-8. DOI:10.1016/j.jaad.2010.12.023 · 5.00 Impact Factor
Article: The great brain versus vein debate[Show abstract] [Hide abstract]
ABSTRACT: From the earliest fMRI experiments, it was quickly appreciated by those working with BOLD at high field that the signal change originated from visible veins whose spatial localization was relatively coarse ("the macrovasculature"), and smaller vessels ("the microvasculature") that were not individually visible in BOLD images. It was expected that a functional brain imaging technique that was predominantly sensitive to the macrovasculature would not have the same effective resolution as one sensitive to the microvasculature. Elimination of the venous signal and enhancement of the microvascular one offered the tantalizing ability to image columnar and lamellar structures in the brain and distinguished fMRI from its predecessor techniques. This article reviews a brief history of how these signal sources were first identified and separated and some of the controversy associated with the "brain versus vein" debate.NeuroImage 09/2011; 62(2):970-4. DOI:10.1016/j.neuroimage.2011.09.005 · 6.36 Impact Factor
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ABSTRACT: Prevalence and risk factors of androgenetic alopecia (AGA) in policemen are not known. This study aimed to compare the prevalence and risk factors of AGA between policemen and the general population. A cross-sectional survey was conducted by recruiting a total of 758 (78%) of 972 policemen and 740 (80%) of 924 participants in a community-based integrated screening served as a comparison group. The Norwood classification system was used to assess the degree of hair loss. Information on age, family history of androgenetic alopecia, and other possible risk factors was collected with questionnaire interviews. The association analysis between policemen and the general population was limited to participants aged 40-59 years. After controlling for other significant factors, policemen aged 40-59 years had an increased risk of developing AGA compared with the general population (OR = 2.23, 95% CI 1.14, 4.36, p = 0.02). Obesity measured by waist circumference and body mass index made contribution to higher risk for AGA in younger policemen (20-39 years). A statistically significant association was noted between AGA and sunlight exposure in policemen aged 40-59 years. We concluded the prevalence of AGA in policemen was twofold higher than that in the general population. Obesity at young age and sunlight exposure may be responsible for higher risk of AGA in policemen. However, further studies are warranted to confirm the current findings.Archives for Dermatological Research 09/2011; 303(10):753-61. DOI:10.1007/s00403-011-1173-5 · 2.27 Impact Factor