[The role of osteocalcin in the connection of bone and glucose metabolism in humans].
The lack of osteoblast derived osteocalcin in mice causes reduced pancreatic beta-cell proliferation, decreased expression of insulin gene and adiponectin gene in adipocytes as well.


METHODS
The relationship between insulin sensitivity, osteocalcin and bone state in 45 healthy (20 females, 25 males) and 92 glucose intolerant (51 females, 41 males) subjects was examined. Body composition, bone density, markers of bone resorption and formation as well as glucose uptake (M value for insulin sensitivity) measured by hyperinsulinemic normoglycemic clamp were determined separately in males and females.


RESULTS
Osteocalcin levels were similar in the two genders, however, glucose intolerant men had lower osteocalcin levels than healthy men (24.5+/-11 vs. 18.1+/-9 ng/ml, p < 0.05). In the healthy group, we found positive correlation between osteocalcin and muscle M values (females: r = +0.319, p < 0.05, males: r = 0.481, p < 0.01), although this relationship disappeared in the glucose intolerant groups. Osteocalcin did not show correlation with adiponectin level in any of the genders. Based on a multivariate regression analysis, in all females significant independent predictors of osteocalcin level were fasting blood glucose, whole and lean body mass glucose uptake, metabolic clearance rate, estradiol and LDL-cholesterol levels (determined 92% of its value), while in all men these were serum calcium, OGTT glucose area under the curve, free fatty acid levels, insulogenic index, HOMA-R and waist/hip ratio (determined 95% of its value). The BMU index characterizing bone resorption/formation correlated significantly with the M values only in women.


CONCLUSIONS
This study confirmed the relationship between insulin sensitivity and osteocalcin in healthy human population, although basic difference was found between the two genders which was not related to osteocalcin.
Buday
Barbara
B
DRC Kft. Balatonfüred Ady E. u. 12. 8230.
Kulcsár
Eniko
E
Literáti Nagy
Botond
B
Horváth
Tünde
T
Vitai
Márta
M
Vecsei
Istvánné
I
Bezzegh
Katalin
K
Kiss
József
J
Péterfai
Eva
E
Koltay
László
L
Korányi
László
L
D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D001786:Blood Glucose / Q000378:metabolism; D015519:Bone Density; D001862:Bone Resorption / Q000378:metabolism; D001842:Bone and Bones / Q000378:metabolism*; D002118:Calcium / Q000097:blood; D008078:Cholesterol, LDL / Q000097:blood; D004958:Estradiol / Q000097:blood; D005230:Fatty Acids, Nonesterified / Q000097:blood; D005260:Female; D005947:Glucose / Q000378:metabolism*; D015309:Glucose Clamp Technique; D018149:Glucose Intolerance / Q000378:metabolism*; D005951:Glucose Tolerance Test; D006801:Humans; D007328:Insulin / Q000097:blood / Q000378:metabolism*; D008297:Male; D008657:Metabolic Clearance Rate; D008875:Middle Aged; D015999:Multivariate Analysis; D015675:Osteocalcin / Q000097:blood / Q000378:metabolism*; D011237:Predictive Value of Tests; D012307:Risk Factors; D012737:Sex Factors; D049629:Waist-Hip Ratio
D015415:Biomarkers; D001786:Blood Glucose; D008078:Cholesterol, LDL; D005230:Fatty Acids, Nonesterified; D007328:Insulin; D015675:Osteocalcin; D004958:Estradiol; D005947:Glucose; D002118:Calcium