As is evident from our data, there is a strong relationship between leptin, adiponectin, and abdominal obesity with increased CVD risk, as assessed by the . However, the leptin-to-adiponectin (L/A) ratio has been proposed as a for reduction of sedentary behaviors 4) advice to achieve five hours per week of .. Vitamin d deficiency in obese children and its relationship to insulin. The relationship between obesity, leptin, adiponectin and the components of metabolic syndrome in urban African women, Free State, South Africa.
But, controversial results have been reported for the relationships between serum 25 OH D levels and anthropometric measures in adolescents. Whereas some studies described significant associations with BMI, global obesity or measures of abdominal obesity [ 1823 ], some others did not find these associations [ 2425 ], suggesting that adiposity might not be the main determinant of vitamin D status in adolescents.
The multivariate linear regression for serum 25 OH D levels, in the current study, showed no significant association with obesity and similar results were found when abdominal obesity was used in the model data not shownsuggesting, as for other authors, that other factors, uncontrolled in the study, could have a stronger effect than obesity to decrease serum vitamin D levels [ 2 ].
Sun exposure time, the degree of skin pigmentation might also contribute significantly to vitamin D status.
Esteghamati et al also reported a linear inverse association between vitamin D and IR in non-diabetics that were independent of obesity [ 26 ]. Authors, in a paediatric study, have reported that low 25 OH D concentrations are related to glucose intolerance and IR particularly in obese people [ 27 ]. Several mechanisms could explain the effect of vitamin D deficiency on insulin sensitivity and its role in promoting IR and glucose abnormalities: Leptin and adiponectin have opposite effects on inflammation and insulin resistance.
High leptin levels increase the expression of pro-inflammatory and pro- angiogenic factors [ 32 ] and, in the same line, vitamin D deficiency predisposes to IR [ 3031 ]. In contrast, adiponectin induces the production of anti-inflammatory cytokines and improves peripheral insulin sensitivity [ 33 ].
The 25 OH D concentrations increased significantly after the 1-year lifestyle intervention confirming that reduction of sedentary behaviours improves vitamin D status, in adolescents. The nutrition counselling and the continual sunniness of our island may have exerted additive beneficial effects on serum 25 OH D levels in the present study even in obese adolescents. Limitations and strengths of the study The potential limitations of our study include i its small sample size, ii the lack of information on food intake affecting serum vitamin D levels such as milk products although milk is not generally supplemented in our countryon time of exposure to solar UV radiation and on measure of outdoor activity at baseline.
Nevertheless, the present study has a number of strengths: In conclusion, insulin resistance that showed a strong association with vitamin D deficiency is common among obese adolescents but, obesity is not the main factor explaining vitamin D deficiency in adolescents. The improvement in 25 OH D level could be due to increasing outdoor physical activity and also to improvement in the nutritional status.
Patricians should encourage adolescents to have a healthier lifestyle with healthy eating, non-sedentary and outdoor activities that may protect against overweight and also improve vitamin D status. Since natural foods rarely contain enough vitamin D to compensate vitamin D deficiency, vitamin D supplementation may be considered and particularly in severely vitamin D deficiency and in very obese adolescents. But, further investigations are needed to better understand the role of vitamin D in the occurrence of insulin resistance.
Acknowledgements We would like to acknowledge all children and parents who participated in the study.
This study was partly supported by grants from the University Hospital of Guadeloupe. This study was partly supported by grants from the University Hospital of Guadeloupe, France. The authors have declared that no competing interests exist. N Engl J Med. Relationship between serum hydroxyvitamin D concentration and risks of metabolic syndrome in children and adolescents from Korean National Health and Nutrition Examination survey Ann Pediatr Endocrinol Metab.
Ghrelin, adipokines, metabolic factors in relation to weight status in school-children and results of a 1-year lifestyle intervention program. Nutr Metab Lond ; Institut de Veille Sanitaire.
Adiponectin | What is Adiponectin? | Adiponectin and Health
The ratio of leptin to adiponectin can be used as an index of insulin resistance. Cardiometabolic risk factors related to vitamin d and adiponectin in obese children and adolescents. Vitamin D deficiency and insulin resistance in obese African-American adolescents.
J Pediatr Endocrinol Metab. Circulating hydroxyvitamin D concentrations are correlated with cardiometabolic risk among American black and white adolescents living in a year-round sunny climate. Vitamin d deficiency in obese children and its relationship to insulin resistance and adipokines. What is the best measure of adiposity change in growing children: Eur J Clin Nutr. Fat cells are biologically active, and their function or dysfunction may affect our health in many ways. For example, fat cells produce and secrete important biologic substances.
One of these substances is called adiponectin. Adipose tissue is a loose connective tissue that is mainly composed of cells called adipocytes. It is possible to assess how much of our body weight is composed of fat. Adipose tissue appears to be an important endocrine organ.
For example, it has been shown that the accumulation of fat around the internal organs may be more harmful than fat accumulation elsewhere. In the s, Professor Jean Vague from the University of Marseille noted that women normally had twice as much fat mass as men 2.
Vague defined two different body shapes. Android obesity or apple shape refers to the accumulation of fat in the upper body are.
Gynoid obesity or pear shape refers to the accumulation of fat on the hips and thighs. The latter is more common among women than men.
However, subcutaneous fat appears much more innocent than visceral fat. In fact, recent studies suggest that abdominal subcutaneous fat is not associated with risk factors for cardiovascular disease 3. The clinical term for low plasma levels of adiponectin is hypoadiponectinemia. Some adipokines may negatively affect health. Studies show that low levels of adiponectin are associated with raised levels of several different markers of inflammation 5. Overall, it appears that losing weight through diet, exercise, medications and surgery will increase adiponectin levels in blood.
Low adiponectin levels are more strongly associated with the amount of visceral fat than subcutaneous fat Development of subcutaneous fat is is an active process in infancy, adolescence and pregnancy In middle aged and elderly people, over nutrition does not lead to an effective storage of energy as subcutaneous fat Instead, visceral fat accumulation becomes more common.
Lifestyle factors such as overeating and physical inactivity in young and middle-age appear to increase the risk of visceral obesity. Adiponectin, Insulin Resistance and Type 2 Diabetes Obesity is associated with high prevalence of insulin resistance and type 2 diabetes.
Several clinical studies have shown that low production of adiponectin correlates with the development of insulin resistance and type 2 diabetes