MERTENS, ILSE L., LUC F. VAN GAAL. Overweight, obesity and blood pressure: the effects of modest weight reduction-a review. Obes Res. 2000;8:270 -278.Several large epidemiological studies have shown an association between body mass index and blood pressure in normal weight and overweight patients. Weight gain in adult life especially seems to be an important risk factor for the development of hypertension. Weight loss has been recommended for the obese hypertensive patient and has been shown to be the most effective nonpharmacological treatment approach. However, long-term results of weight loss programs are disappointing with people often regaining most of the weight initially lost. In recent years, a modest weight loss, defined as a weight loss of 5% to 10% of baseline weight, has received increasing attention as a new treatment strategy for overweight and obese patients. A more gradual and moderate weight loss is more likely to be maintained over a longer period of time. Several studies have confirmed the blood pressure-lowering effect of a modest weight loss in both hypertensive and nonhypertensive patients. A modest weight loss can normalize blood pressure levels even without reaching ideal weight. In patients taking antihypertensive medication, a modest weight loss has been shown to lower or even discontinue the need for antihypertensive medication. In patients with high normal blood pressure, a modest weight loss can prevent the onset of frank hypertension. The blood pressure-lowering effect of weight loss is most likely a result of an improvement in insulin sensitivity and a decrease in sympathetic nervous system activity and occurs independent of salt restriction. In conclusion, a modest weight loss that can be maintained over a longer period of time is a valuable treatment goal in hypertensive patients.

Since the discovery of leptin, a boom of scienti®c knowledge became available about the OB-protein gene and its role and signi®cance in weight regulation. Both from animal and human research data, serum leptin can probably be considered as one of the best biological markers to re¯ect total body fat, and this ®nding is true over a wide range of body mass indexes (BMIs) and in different pathologies: in normal weight, anorexic and obese subjects; in non insulindependent diabetes mellitus (NIDDM) patients, PCO women, Prader-Willi children and subjects with hypogonadism and growth hormone de®ciency.Gender differences clearly exist, probably related to sex hormone differences, and from fat distribution studies it could be shown that subcutaneous fat is much more related to serum leptin concentrations than visceral fat: also leptin messenger-RNA (m-RNA) expression is signi®cantly higher in subcutaneous fat from human obese subjects.Leptin is not only correlated to a series of endocrine parameters such as insulin, insulin-like growth factor, (IGF) and SHBG, it seems involved as a mediator in some endocrine mechanisms (onset of puberty, insulin secretion, etc) as well.Weight loss will reduce human leptin concentrations, whereas the administration of human recombinant leptin seems to show only limited effects.Keywords: leptin; body fat distribution; endocrinology; hormones IntroductionObesity is becoming a major health problem in western countries, with an annual growing incidence and its association with increased morbidity and mortality. Furthermore, obesity is a very complex problem in its development, being a multifactorial disease, as well as in its treatment. Knowledge of the mechanisms by which obesity develops can help in prevention and better treatment. The discovery of leptin 1 and the subsequent wealth of research on the subject, has already led to more insight into these mechanisms. 2 Evidence from the research until now points out that leptin is likely to be a crucial hormone in the regulation of body weight, in humans as well as in animal models. 2 It is clear that leptin plays an important role in the regulation of body weight, more speci®cally of body fat stores. Almost all studies hitherto found a strong relationship between leptin and weight, expressed as body mass index (BMI) or percent body fat. 2 ± 4 But for a certain BMI, a large variability in leptin levels is found. 2,3,5 Also manifest differences in leptin concentration between men and women have been found by different authors. 6,7 Given the close interrelationships between body weight, body fat distribution and many hormonal functions, in energy balance regulation, leptin may play an important and triggering role as a hormonal determinant of energy balance in addition to the well-known role played by insulin, catecholamines, glucagon 8 and thyroid hormones. 9 As it is a fact that leptin and its receptor are two important components of a homeostatic system regulating body fat, it is likely that the process of leptin's signalling by the hypothalam...

No abstract

No abstract