Linolenic and linoleic acids, two major dietary sources of HDL, are 5 alpha reductase inhibitors. Premature androgenic alopecia and insulin resistance may be a clinical constellation that represents the male homologue, or phenotype, of polycystic ovary syndrome. Others have found a higher rate of hyperinsulinemia in family members of women with polycystic ovarian syndrome. With early-onset AGA having an increased risk of metabolic syndrome, poorer metabolic profiles are noticed in those with AGA, including metrics for body mass index, waist circumference, fasting glucose, blood lipids, and blood pressure.In support of the association, finasteride improves glucose metabolism and decreases glycosylated hemoglobin HbA1c, a surrogate marker for diabetes mellitus. The low SHBG seen with premature androgenic alopecia is also associated with, and likely contributory to, insulin resistance, and for which it still is used as an assay for pediatric diabetes mellitus.Obesity leads to upregulation of insulin production and decrease in SHBG. Further reinforcing the relationship, SHBG is downregulated by insulin in vitro, although SHBG levels do not appear to affect insulin production. In vivo, insulin stimulates both testosterone production and SHBG inhibition in normal and obese men. The relationship between SHBG and insulin resistance has been known for some time; decades prior, ratios of SHBG and adiponectin were used before glucose to predict insulin resistance.
Supplementing eunuchs with testosterone during their second decade, for example, causes slow progression of androgenic alopecia over many years, while testosterone late in life causes rapid hair loss within a month.An example of premature age effect is Werners syndrome, a condition of accelerated aging from low-fidelity copying of mRNA. Affected children display premature androgenic alopecia.Permanent hair-loss is a result of reduction of the number of living hair matrixes. Long-term of insufficiency of nutrition is an important cause for the death of hair matrixes. Misrepair-accumulation aging theory    suggests that dermal fibrosis is associated with the progressive hair-loss and hair-whitening in old people. With age, the dermal layer of the skin has progressive deposition of collagen fibers, and this is a result of accumulation of Misrepairs of derma. Fibrosis makes the derma stiff and makes the tissue have increased resistance to the walls of blood vessels. The tissue resistance to arteries will lead to the reduction of blood supply to the local tissue including the papillas. Dermal fibrosis is progressive; thus the insufficiency of nutrition to papillas is permanent. Senile hair-loss and hair-whitening are partially a consequence of the fibrosis of the skin. Diagnosis
The diagnosis of androgenic alopecia can be usually established based on clinical presentation in men. In women, the diagnosis usually requires more complex diagnostic evaluation. Further evaluation of the differential requires exclusion of other causes of hair loss, and assessing for the typical progressive hair loss pattern of androgenic alopecia. Trichoscopy can be used for further evaluation.