Leptin of dermal adipose tissue is differentially expressed during the hair cycle and contributes to adipocyte-mediated growth inhibition of anagen-phase vibrissa hair.

Exp Dermatol. 2014 Oct 14. doi: 10.1111/exd.12566. [Epub ahead of print]
Leptin of dermal adipose tissue is differentially expressed during the hair cycle and contributes to adipocyte-mediated growth inhibition of anagen-phase vibrissa hair.
Yang CC1, Sheu HM, Chung PL, Chang CH, Tsai YS, Hughes MW, Tuan TL, Huang LL.

Adipose tissue encircles the lower portion of anagen hair follicles and may regulate hair cycle progression. Since leptin is a major adipokine, its level of expression from the dermal white adipose tissue during hair cycle progression was studied. The result shows that leptin level is differentially expressed during hair cycle, the lowest in early anagen, upregulated in late anagen, and the highest in the telogen phase. On the other hand, leptin receptor is detected in keratin 15-positive hair bulge epithelium of both anagen and telogen-phase hair follicles of mice pelage and vibrissa hair, and hair from human scalp. Leptin contributes to adipocyte-mediated growth inhibition of anagen-phase vibrissa hair as demonstrated in organ culture and co-culture system. Our data suggests that leptin of dermal white adipose tissue might regulate hair growth and, therefore, hair cycle progression via leptin receptor on the hair follicle epithelium.

As a guy with a focus on the genetics, this definitely shows genetics aren't the be-all-end-all. Dietary influences happening here.