Inverse association between serum resistin and insulin resistance in humans.

AIM: To determine how serum concentrations of resistin are distributed in humans in relation to insulin resistance, type 2 diabetes, and obesity. METHODS: Cross-sectional, descriptive study carried out in a random sample (n=713, 43% men, 18-75 years) of general population of inhabitants of the Canary Islands (Spain). Serum resistin concentration, HOMA2-IR, anthropometric parameters, drug consumption and physical activity were recorded. RESULTS: There were no differences in resistin concentration between participants with and without diabetes (3.1+/-0.2 vs. 3.2+/-0.1ng/mL; p=0.566), or between obese and non-obese participants (3.1+/-0.1 vs. 3.2+/-0.1ng/mL; p=0.803). Individuals with abdominal obesity (waist-hip ratio [WHR] >or=1 in men or >or=0.9 in women) had lower concentrations of resistin (3.0+/-0.13 vs. 3.4+/-0.1ng/mL; p<0.001). The correlations between resistin and HOMA2-IR (r=-0.231; p<0.001) and between resistin and WHR (r=-0.202; p<0.001) were inverse. Multivariate analysis corroborated the inverse association of this cytokine with HOMA2-IR, WHR and, in women, also retained in the model the direct association between resistin and physical activity and the inverse association between resistin and antihypertensive agents. CONCLUSIONS: In this population resistin is inversely associated with insulin resistance and abdominal obesity.

Serum resistin and polymorphisms of androgen receptor GAGn and GGNn and aromatase TTTAn.

There is evidence that androgens are regulators of insulin resistance (IR), and may be involved in the regulation of resistin, a cytokine that has been related with IR. Earlier studies found that androgen receptor length polymorphisms CAGn and GGNn and the aromatase polymorphism TTTAn may influence receptor or enzyme activity and serum concentrations of androgens. This study was designed to determine whether polymorphism length was related to serum resistin concentration and to other variables related with IR. In 1,580 persons chosen randomly from the general population of the Canary Islands (Spain), we measured polymorphism length, waist circumference, waist/hip ratio, BMI, and serum glucose concentration. In smaller subgroups, we also measured C-peptide (n = 677), resistin (n = 583), and leptin concentration (n = 754) and estimated IR (homeostasis model assessment-IR (HOMA2-IR)). In men, polymorphism length correlated with resistin concentration (CAGn, r = 0.13, P = 0.031; TTTAn, r = 0.15, P = 0.005; GGNn, r = -0.15, P = 0.026), and the correlations were confirmed in multivariate regression models. The length of CAGn and TTTAn correlated inversely with C-peptide (r = -0.13, P = 0.016 and r = -0.21, P < 0.001, respectively) and with estimated IR (r = -0.12, P = 0.032 and r = -0.19, P = 0.001, respectively). In men, length of the CAGn, GGNn, and TTTAn was associated with serum resistin concentration. These results support the hypothesis that androgens may be involved in the regulation of resistin. Resistin may be a link between IR and androgens.

High density lipoprotein cholesterol increases with living altitude.

BACKGROUND: The relationship between high density lipoprotein cholesterol (HDL) serum level and the altitude at which people live is controversial. METHODS: A cross-sectional study was carried out in the adult population (30-64 years) of the Island of El Hierro (Canary Islands, Spain). In all, 594 individuals representative of the El Hierro population for gender, age, district and the altitude at which they lived were included. The factors measured included HDL, living altitude, body mass index (BMI), smoking habits, alcohol consumption, diabetes, menopause in women, and physical activity and dietary habits. RESULTS: The HDL showed a correlation with living altitude (r = 0.14, P < 0.01) and with BMI (r = -0.19, P < 0.01). Smokers had lower HDL levels than ex-smokers and non-smokers (P < 0.05). Men who were moderate drinkers had higher HDL levels than heavy or mild drinkers and non-drinkers (P < 0.01). Physical activity was only related to HDL in men with levels >1.52 mmol/l, who walked on the average more than the rest (P < 0.05). Variables not showing the expected relationship with HDL were diabetes and the menopause in women (probably due to a low statistical power of their subsamples). Regression analysis, with HDL as dependent variable showed that the association between HDL and altitude persists when taking altitude as a categorical or a continuous variable. CONCLUSIONS: High density lipoprotein cholesterol levels are linearly and significantly increased when living at a higher altitude. This fact should be taken into account when comparing cardiovascular risk in populations living at different altitudes.

[Smoking habit among workers of the public health system in Tenerife]. / Hábito tabaáquico en los trabajadores del sistema sanitario público de Tenerife.

OBJECTIVE: To find the prevalence of tobacco use among workers in the Public Health system and to assess their own attitudes to the possibility of giving up smoking. DESIGN: A descriptive study of a crossover type was carried out using a self-filled closed-answer questionnaire. SETTING: The Public Health system on the island of Tenerife. PARTICIPANTS: After stratified random sampling, a sample of 1,282 workers was obtained, of whom 770 (60%) answered the questionnaire. Later a reply was obtained from 10% of those who did not at first reply, without any differences from the other participants being apparent. MEASUREMENTS AND MAIN RESULTS: Overall prevalence is 43% of smokers, 13% ex-smokers and 44% non-smokers. 20% of the smokers have an important physical dependency and only 30.76% are highly motivated to stop smoking. 56% of smokers feel home pressure to stop smoking, while only 29.5% of smokers feel pressured at work. We elaborated a scale, which was useful in measuring peoples' motivation to abandon the habit. CONCLUSIONS: Almost half these workers are smokers at present. Despite belonging to the Health system, they are no more motivated than the general population they look after.