Low serum leptin concentration in vegeta­rian prepubertal children
Ambroszkiewicz J, Laskowska-Klita T, Klemarczyk W

Purpose: Vegetarian diet may play a positive role in reducing risk of several chronic diseases such as diabetes, coronary heart disease and some types of cancer. There are different vegetarian dietary patterns, some of which are nutritionally adequate for children, whereas other may lack some essential nutrients. Leptin, a hormone from adipose tissue plays a key role in the control of body fat stores and energy expenditure. Higher leptin levels were observed in obese subjects and lower in anorectic patients. Recent studies support that diet may be a factor which influences leptin levels. The aim of this study was to investigate serum concentrations of leptin, lipids and apolipoproteins in prepubertal children with two different nutritional habits: vegetarian and omnivorous diet.
Material and methods: We examined 22 vegetarians and 13 omnivores in age 2-10 years. Serum leptin concentration was determined by immunoenzyme assay (ELISA) and serum lipids were measured by enzymatic and immunoturbidimetric methods.
Results: Average daily dietary energy intake and the percentage of energy from protein, fat and carbohydrates were similar for both groups of children. We observed that in vegetarian diet there is a high rate of fiber nearly twice as high as in omnivorous diet. Vegetarians had lower total cholesterol and HDL- and LDL-cholesterol concentrations than children on traditional mixed diet. There is no significant differences in trigliceride concentration between studied groups. The apolipoproteins levels in vegetarian children were significantly below that of omnivores. The serum concentration of leptin was lower in vegetarians (3.0±1.1 ng/mL) than in nonvegetarians (5.1±2.0 ng/mL) (p<0.01).
Conclusions: Our results suggest that vegetarian diet may be accompanied by lower serum leptin concentration. Further studies on large group of children are needed for understanding this problem better.

Key words:   leptin, lipids, vegetarian diet, prepubertal children.