Prevalence of overweight and obesity in Sardinian adolescents

BACKGROUND

To estimate the prevalence of overweight and obesity among adolescents in Sardinia and to examine the association with several biological and geographic factors.

METHODOLOGY

A cross-sectional study was performed in 3,946 unselected adolescents (2,011 boys, 1,935 girls; aged 11-15 years) attending the public secondary schools in 33 Sardinian municipalities: 28 semi-rural, 5 urban, sub-grouped according to their geographic location (mountain, hillside and plain). Oversized children were measured and their BMI defined as being above normal values according to parameters provided by the International Obesity Task Force (IOFT) by Cole et al. (BMI for age > or = 95th percentile). Relative risk for overweight and obesity was calculated using Poisson regression analysis: risks associated to each covariate were reciprocally adjusted. The 95% confidence interval (CI) of the estimated risk was calculated using Wald's formula (RR, RR = log(n) beta +/- 1.96 se(beta)).

MAIN FINDINGS

The overall prevalence rate found for overweight and obesity was 14.9% (95% C.I.: 13.7-16.1%) and 3.7% (95% C.I. 3.1-4.3%), respectively. Overweight rate showed no association with gender, whereas belonging to the female sex constituted a significant protection against obesity. Increasing age in the range 12-14 years was protective against both overweight and obesity in the whole sample. A similar finding however was not observed for obesity in girls or overweight in boys, when considered separately. Boys, but not girls, living in urban areas displayed a modest though significant 20% increase in overweight and a 40% decrease in obesity risk. Living in a mountainous area conveyed a 30% decrease in risk of overweight and a 50% decrease in risk of obesity, when compared to living on the plains and hillside combined. However, the small sample size of study subjects living in mountainous areas generated extremely wide 95% confidence intervals, thereby preventing the drawing of any significant conclusions.

CONCLUSION

In comparison with other surveys performed by the IOFT, Sardinian adolescents show a low prevalence rate for oversize, emphasizing a marked discrepancy with the general north-south rising trend of oversize observed throughout Europe. Geographic location, aesthetic or other age related factors seem to exert a different gender-specific influence on overweight and obesity.

SIGNIFICANCE

The present report is cross sectional and the consequences of overweight and obesity on individuals over time are not traceable. However, the outcome of the study suggests the need to implement suitable policies and public health programs leading to increased awareness.

High serum circulating telopeptide type I in multinodular goiter

Recently, concentrations of serum carboxy-terminal-1-telopeptide (ICTP), a marker of bone collagen resorption, were found to be more sensitive than sex hormone-binding globulin (SHBG) in identifying peripheral overexposure to thyroid hormones in exogenous subclinical hyperthyroidism. The aim of the present study was to assess serum ICTP and SHBG in multinodular goiter with (pretoxic goiter) or without biochemical evidence of endogenous subclinical hyperthyroidism. Forty-five women affected by multinodular goiter were enrolled in this study. They were subdivided into two groups: group 1, consisting of 27 patients affected by pretoxic goiter; group 2, consisting of 18 patients affected by non toxic goiter; group 3, consisting of thirty-six euthyroid women matched with the other groups for age and lifestyle. In group 1, serum ICTP (mean +/- SD: 5.8 +/- 2.9 microg/l) concentrations were significantly higher when compared either to group 2 (3.6 +/- 1.2 microg/l; p < 0.02) or controls (2.7 +/- 0.7 microg/l; p < 0.0001); serum ICTP concentrations were also slightly but significantly higher in patients of group 2 compared to controls (p < 0.003). In contrast, mean serum SHBG concentrations did not show any difference among the three groups. No significant correlation was found between serum TSH and ICTP concentrations, while a weak positive correlation (p < 0.05) was only found between serum FT 3 and ICTP concentrations when data from the two patient groups were analyzed together. Moreover, when we subdivided patients into pre- and postmenopausal patients, we observed that SHBG but not ICTP serum concentrations were influenced by estrogenic status. In summary, the measurement of serum ICTP seems to be more suitable than SHBG for identifying those with a higher degree of peripheral thyroid hormone exposure in women affected by endogenous subclinical hyperthyroidism.

Circulating telopeptide type I is a peripheral marker of thyroid hormone action in hyperthyroidism and during levothyroxine suppressive therapy

The aim of the present investigation was to evaluate the clinical performance of serum carboxy-terminal-1-telopeptide (ICTP), a new marker of bone resorption, in identifying peripheral overexposure to thyroid hormones, as compared with serum osteocalcin (OC) and serum sex hormone binding globulin (SHBG). Serum ICTP, SHBG, and OC were assayed by specific radioassays in three study groups. Group 1: 50 perimenopausal women on long-term levothyroxine (LT4) suppressive treatment; group 2: 29 women with untreated hyperthyroidism; group 3: 36 normal euthyroid women matched with group 1 patients for age, alcohol, smoking habits, and lifestyle. Serum concentrations of SHBG, ICTP, and OC were markedly increased in hyperthyroid patients, whereas only serum ICTP was slightly but significantly increased in LT4 treated patients. Serum ICTP had higher diagnostic value for hyperthyroidism when compared with SHBG and to OC (sensitivity: 100%, 71%, 55%; accuracy: 97%, 88%, and 76%, respectively). In group 1, increased serum ICTP was observed in 30 of 50 patients, whereas increased SHBG and OC were found only in 11 of 50 (p < .001). Serum free thyroid hormone concentrations correlated with circulating ICTP and SHBG, and the correlation with serum OC was of lower significance. In conclusion, serum ICTP is a sensitive and reliable marker of peripheral thyroid hormone activity at the bone level; its clinical performance is higher than OC and even better than SHBG. Thus, serum ICTP is better than other peripheral markers in monitoring LT4 suppressive therapy in patients at increased risk for osteoporosis such as perimenopausal women.