Kisspeptin is a key player in the central control of reproductive axis. Central administration of kisspeptin has been shown to advance puberty in rats. Stimulation of hypothalamic GnRH pulse generating mechanism by kisspeptin has been proposed to be the mechanism behind the onset of puberty. We hypothesized that chronic high doses of kisspeptin administration suppresses the reproductive axis and hence delays the pubertal onset. Hence, we investigated the effect of peripheral administration of chronic high doses of kisspeptin on pubertal onset, feed intake and body weight in female rats. Rats were treated with saline or kisspeptin (100 nmoles per day; intraperitoneal) for 26 days (day 25 to day 50 postnatal) and the day of vaginal opening was marked as day of puberty. Kisspeptin treated rats had delayed pubertal onset and reduced feed intake and body weight. Gonadal GPR54 mRNA was reduced suggesting that chronic high doses of kisspeptin may suppress the reproductive functions possibly by downregulation of GPR54 receptor. However, delay in puberty due to reduction in feed intake and body weight could not be ruled out in this study. Further, our study emphasizes the importance of dosage and duration of kisspeptin administration in the manipulation of reproductive axis. Our study, for the first time, suggests that kisspeptin and its analogues, if proven beneficial, could be used to treat precocious puberty in children. It appears that, though a promising tool for enhancing fertility, kisspeptin acts as a double-edged sword and has to be cautiously used to manipulate reproduction.

The purpose of this study was to investigate the current status of chronic diseases according to obesity in the elderly older than age 65 using data from the 7th Korea National Health and Nutrition Examination Survey (2016~2018). The subjects of the survey were 3,245 elderly older than age 65 who participated in the health survey and nutrition survey, 45.8% of the subjects were males and 54.2% of the subjects were female. 37.5% of all the elderly were obese, and the females (42.4%) were more obese than the males (31.8%) (p<0.001). Diabetes, hypertension, and hypertriglyceridemia had a similar prevalence of 24.6%, 63.0%, and 12.7% in males and females, respectively. Hypercholesterolemia was higher in the elderly females (44.2%) than in the elderly males (24.9%) (p<0.001). Through the logistic regression analysis, it was found that the prevalence of chronic diseases was higher in obesity than normal in elderly males and females (p<0.001). The total food intake increased from ‘under weight’ to ‘obesity’ in males (p<0.01) and females (p<0.001). In the case of the elderly males, the higher the degree of obesity, the higher the energy intake (p<0.05), and ‘pre-obesity’ consumed the most energy in elderly females. As a result of this study, the higher the obesity rate of the elderly, the higher the prevalence of chronic diseases.