Age-related changes in bone density among healthy Greek males.

Osteoporosis in men is increasingly recognized as a problem in clinical medicine, but it has received much less attention than its counterpart in women. It is termed idiopathic if no known cause of bone disease can be identified clinically or in the laboratory. The true incidence of idiopathic osteoporosis (IO) in males is difficult to estimate because population characteristics and referral patterns differ so widely. The aim of this study was to investigate the incidence of IO in healthy Greek male volunteers by measuring bone mineral density (BMD) at four skeletal sites and examining the relations among age, BMI, and bone status. This type of information has not yet been published. We considered osteoporosis to be present when the BMD was less than or equal to -2.5 SD from the average value for healthy young men. Three hundred and sixty-three normal male volunteers were investigated. The mean age was 51.3+/-8.7 yr, and BMI was 27.5+/-3.7 kg/m2. In all subjects BMD at four skeletal sites - lumbar spine (LS), femoral neck (FN), Ward's triangle (WT), and finally trochanter (T) - was measured using dual-energy X-ray absorptiometry (DEXA). T-score, Z-score and g/cm2 values were estimated. Forty-four subjects (11%) had BMD< or =-2.5 SD (T-score). The mean age and BMI for the men with decreased BMD was 54.8+/-6.4 yr and 26.3+/-3.3 kg/m2, whereas mean age and BMI for those with normal BMD was 51.0+/-8.9 yr and 27.6+/-3.6 kg/m2, respectively. These differences were statistically significant (p<0.001 and p<0.05, respectively). A positive correlation was found between BMI and bone density (g/cm2) at three skeletal sites: LS (r=0.235, p<0.001), WT (r=0.126, p<0.001) and FN (r=0.260, p<0.001). A positive correlation was also found between BMI and T-score at all skeletal sites studied: LS (r=0.276, p<0.001), WT (r=0.133, p<0.05), FN (r=0.233, p<0.001), and T (r=0.305, p<0.001). Finally, a positive correlation was also found between BMI and Z-score: LS (r=0.256, p<0.001), WT (r=0.117, p<0.005), FN (r=0.240, p<0.001), and T (r=0.187, p<0.001). A negative correlation was found between age and bone density (g/cm2) at FN (r=-0.157, p<0.01) and WT (r=-0.183, p<0.001). The same was true between age and T-score at FN only (r=0.137, p<0.05). Furthermore, a similar correlation was found between age and Z-score at LS (r=0.174, p<0.001). When ANOVA one-way analysis was used, a significant difference was found between the different age groups and BMD (g/cm2) at FN, T, and WT (p<0.001 for all sites). For T-score, a significant difference between age groups was found only at FN (p<0.005). Finally, a significant difference in Z-score was found at FN (p<0.001) and LS (p<0.005). When multiple regression analysis was applied, it was found that BMD (g/cm2) at two sites, FN and WT, independently correlated with age and BMI (FN: p<0.001 for both, WT: p<0.01 and p<0.05, respectively). Finally, we found an accelerated trend toward decreased BMD (g/cm2), when the odds ratio was applied. In conclusion, this study demonstrated that 11% of otherwise healthy Greek men had BMD less than or equal to -2.5 SD. A strong association was found between BMD (g/cm2) and age at three skeletal sites when ANOVA one-way analysis was applied. Moreover, BMD was positively correlated with BMI and negatively correlated with age. Currently available data are sparse and much more research is needed to increase our understanding concerning the etiology of this condition as well as illuminating the relationship between bone density and fracture.

Leptin levels in maternal and cord serum: relationship with fetal development and placental weight.

OBJECTIVE: To test the hypothesis that the circulating levels of leptin in the maternal and cord serum correlate with the birthweight of the newborns and with the weight of the placenta. METHODS: In a population of 85 women from northern Greece who gave birth to an equal number of full-term infants, we calculated the concentration of leptin in the maternal serum as well as in the cord serum, right after delivery, by using an immunoradiometric assay. The correlation between these values, the maternal BMI before pregnancy and at the time of delivery, the neonatal BMI, Ponderal Index, and the placental weight was studied. RESULTS: Mean maternal leptin showed a statistically significant difference from mean cord serum leptin (14.7 and 7.07 ng/ml, respectively) and was positively correlated to the maternal BMI at the time of delivery (r = 0.3, P = 0.016), but not to neonatal BMI. A positive correlation between the mean cord serum leptin and the BMI of the neonates (r = 0.26, P = 0.031 ) was found. There was no correlation between the maternal BMI at the time of delivery and the neonatal BMI. Similarly, no correlation could be established between the placental weight and the levels of leptin in the maternal or in the cord serum but a positive correlation between placental weight, neonatal BMI and weight, and mothers' BMI was observed. Finally, although a noteworthy difference between the mean leptin levels of neonates of two different sexes was observed (male 5.9 ng/ml, female 7.8 ng/ml), that difference never reached a statistically significant level. CONCLUSIONS: The maternal leptin level could not be used as a reliable marker of fetal growth but a positive correlation between cord serum leptin and fetus growth is suggested.