Variations in skinfold thickness during de-acclimatisation and re-acclimatisation to high altitude. Relation to body fat content

Ghrelin and leptin levels of sojourners and acclimatized lowlanders at high altitude

The circulatory levels of two appetite regulatory hormones i.e. leptin and ghrelin were estimated in sojourners and acclimatized subjects to investigate their possible role in high altitude (HA) induced anorexia. A group of 30 lowlanders who had never visited HA were inducted to a height of 3600 m by air and after 48 h they were further taken to an altitude of 4300 m by road. Blood samples were collected after 48 h stay at 3600 m and again after 48 h and 7 days of stay at 4300 m during 0700-0730 h. There was a decrease in energy intake (850 kcal/day) of sojourners, which resulted in loss of body weight by 2.12 kg at HA. At an altitude of 4300 m there was a significant increase in leptin over basal levels (54.9%, p < 0.001) at 48 h that persisted even after 7 days of stay at this altitude. Ghrelin levels of sojourners decreased by more than 30% in comparison to basal values at 48 h of ascent to HA. Leptin levels of acclimatized lowlanders were also higher in comparison with control group (acclimatized group 7.6 + 0.6 ng/ml vs. control 5.6 + 0.5 ng/ml, p < 0.01, n = 50).

Can body fat patterning be changed?

Short- and long-term weight reduction programmes both resulted in a significant decrease in the waist/hip ratio (WHR) among obese premenopausal women. In matched groups of women with gynoid and android obesity, the latter demonstrated a greater decrease in WHR after 1 year's weight reduction and, at the same level of body weight loss, a consistently lower decrease in the lean body mass. Gluteal fat cells were found to empty at a slower rate than those in the abdominal region, particularly in gynoid obesity. After 1 year's weight reduction, the decrease in WHR correlated significantly with decreases in body weight, blood pressure and metabolic variables. Six months' physical training with and without reduction of body weight resulted in a significant decrease in WHR, while one-leg exercise caused a local decrease in the circumference of the trained leg. Reduction of flatulence in obese men was also found to be associated with decreased WHR.

Role of neuropeptide Y and galanin in high altitude induced anorexia in rats

Anorexia causing weight loss at high altitude (HA) is a major problem. Neuropeptide Y (NPY) and galanin are considered to have appetite regulatory function. The present study was therefore undertaken to investigate the changes in these two peptides at simulated HA and its possible role in anorexia. Male Sprague-Dawley rats (n = 8 in each group) were exposed to simulated HA (7620 m) for 1, 7, 14 and 21 days for 6 h a day and to an altitude of 6,096 m for 72 h to study the effect of intermittent and continuous exposure, respectively. NPY and galanin levels were estimated in different brain parts and plasma of exposed and unexposed control animals. Significant reduction in food intake was observed in rats during both intermittent as well as continuous exposure. In case of 72 h continuous exposure severe reduction in food intake was observed (73.2%) with reduction in body mass (approximately 29.7g/rat in 48h). Hypothalamic NPY levels were decreased by 54.7, 35.0 and 15.4% in 1, 7, and 14 days, respectively, in case of intermittent exposure to HA. However in case of 72 h HA exposure no significant change in hypothalamic and circulating NPY levels were observed. Plasma galanin levels were decreased in both intermittent and 72 h continuous HA exposed rats. Hypothalamic galanin levels were also decreased in 72h exposed rats. The changes in levels of these peptides may be responsible for anorexia at HA.