High altitude and nail growth.

Linear nail growth studies were carried out in 22 highlanders Ladakhi (3445 m) and 6 lowlander male troops, in 4 during their fresh induction into high altitude (3445 m) and in 2 during their stay in plains while on leave from high altitude. The average age of highlander Ladakhis was 21.82 years (range 16-36 years) and lowlanders was 34 years (range 29-40 years). There was significant decrease in nail growth in age matched (average age 34.25) highlander Ladakhis (93.11/day, SD 7.24, P < 0.05) and in freshly inducted lowlanders (88.71/day, SD 10.7 mu, P < 0.05) in contrast to average nail growth in plains (1191/day, SD 1.41) Although the average nail growth in highlander Ladakhis (99.34/day, SD 13.91) was more than the lowlanders inducted into high altitude (88.7 s/day, SD 10.7 mu) the difference was not found statistically significant (P > 0.05). However it does suggest some degree of acclimatization in highlanders. Hypoxic conditions and extreme cold conditions both appear to be factors responsible for decreased nail growth in high altitude areas.