Osteoporosis and polymorphisms of osteoprotegerin gene in postmenopausal women - a pilot study.

OBJECTIVES: Osteoprotegerin (OPG) has an important role in bone remodeling, and it has been proposed that the OPG gene might be a candidate gene for osteoporosis predisposition. Several studies have already assessed the connection between OPG gene polymorphism and bone mineral density (BMD). In this study we wanted to analyze the association of two polymorphisms in the OPG gene with BMD and bone turnover markers in women with and without osteoporosis. MATERIAL AND METHODS: In 22 postmenopausal women with osteoporosis (aged 65.6 ±12.6) and 59 women without osteoporosis (aged 60.8 ±8.7) we analyzed the association of two polymorphisms in the OPG gene with BMD, measured by dual energy absorptiometry and with bone turnover markers (crosslaps and osteoprotegerin). A163G, G209A, T245G and G1181C polymorphisms were determined. RESULTS: No significant differences in age, anthropometry, number of fractures, osteocalcin and cross-laps were found between women with and without osteoporosis. Women with osteoporosis were significantly longer in postmenopause. Significantly more women with osteoporosis had AG polymorphism (p = 0.038) compared to women without osteoporosis, while no significant difference was found in prevalence of TT and GG polymorphism between patients with and without osteoporosis. No relationship was found between investigated polymorphism and bone turnover markers. A significant negative correlation between total hip BMD and crosslaps (p = 0.046) as well as between total hip T score and crosslaps (p = 0.044) was found in women without osteoporosis. CONCLUSIONS: Postmenopausal women with osteoporosis had AG polymorphism more frequently than women without osteoporosis. Our results indicate that A163G polymorphism could have an impact on higher bone loss in postmenopausal women.

Low adiponectin serum level--reduced protective effect on the left ventricular wall thickness.

Adiponectin, secreted by fat tissue, is down - regulated in obesity and may be involved in obesity-related disorders. It has anti-inflammatory, antiatherosclerotic and antidiabetic effect. Obesity is a strong predictor for hypertension and cardiovascular diseases. Recent studies showed that adiponectin level has important role in metabolic disorders, arterial hypertension and ischemic heart disease but its effect on left ventricular hypertrophy (LVH) has not been fully clarified. The aim of this research is to determine whether the protective effect of adiponectin against development of left ventricular hypertrophy is decreased in hypertensive overweight patients. The study included 61 adult, overweight hypertensive patients, with body mass index in range 25-30 kg/m2. Patients had regular morning glucose serum values and regular creatinine level. They were divided into four groups, according to sex and the presence of LVH. There were 16 female and 15 male hypertensive patients with LVH and 15 female and 15 male hypertensive patients without LVH, who were a control group. Glucose profile, lipidogram, creatinine clearance and anthropometric measures were determined in all patients. Cardiovascular measurements were taken applying two-dimensional ultrasound. Adiponectin serum level was measured using enzyme immunoassay (ELISA). Results showed that adiponectin serum level was significantly lower in hypertensive, overweight females and males with LVH than in the control groups without LVH. Adiponectin serum level did not correlate significant with intraventricular or with posterior wall thickness of left ventricle. Hypoadiponectinemia presents part of neurohumoral, non-haemodynamic system who contributes to obesity-related hypertension and left ventricular hypertrophy development. Low adiponectin level together with others adipokines, cytokines and chemokines secreted by fat tissue could contribute to pathophysiologic changes of the myocardium via unknown molecular mechanisms yet.

Circadian rhythm of blood leptin level in obese and non-obese people.

Leptin, an adipose tissue hormone, has circadian variations in its secretion. Aims of this study were to show how circadian rhythm depends on fat tissue distribution in obese and non-obese subjects. The research was carried out on 70 subjects (37 men and 33 women) with an average body mass index (BMI) of 25.22 kg/m2. Concentration of leptin in blood was measured at 8.30 a.m., 12.30 p.m. and 6.30 p.m. Basal leptin level correlated strongly with all isolated regions of subcutaneous fat tissue in women and obese subjects. Circadian changes of blood leptin level in non-obese people are more significant than these changes in obese people. Differences in circadian pattern of leptin secretion between obese and non-obese subjects were probably caused by enlarged volume of subcutaneous fat tissue in obese people. Lean subjects have subcutaneous fat in physiological range which allows influence of some hormones (insulin or cortizol) or food intake on leptin secretion.