The Relationship Between BGP, P1Np And β-CTx With Type2Diabetes Mellitus

Background&ObjectiveOsteoporosis is one of the common complications of diabetes mellitus. For the past few years, the research of the relationship between the bone metabolism and the diabetes mellitus is highly valued by the scholars. Serum osteocacin(BGP), total procollagen type1N-propeptide(PlNP), p-cross-linked c-terminal telopeptide of type1collagen (p-CTX) are the widely used parameters of bone metabolism. The process of bone metabolism is disturbed by the deficiency of insulin, hyperglycemia, the accumulation of advanced glycosylation end products(AGEs) and the osmotic diuresis caused by high blood glucose. The effect of bone resorption is more than formation, resulting in osteoporosis. However, can bone react to the series of negative influences and secrete some substance regulating the glucose and lipid metabolism? Lee is the first person who finds it is BGP that regulates the energy metabolism.Rencently the reasearch of effect of BGP on islet cell function and insulin sensitivity in human is rare at home and abroad. This research makes correlations between the serum BGP, P1NP,0-CTx and HOMA-CR, HOMA-β, C-peptide area under curve(CAuc), body mass index(BMI), serum total cholesterol (TC), serum total triglyceride (TG), fasting blood glucose(FBG), hemoglobin Ale (HbAlc), discussing if bone can act as an endocrine organ and has an effect on the metabolism of glucose and lipid, accociating with the development of diabetes mellitus.Subjects and Methods1. Subjects collection The data are from premenopausal females and males inpatients who were diagnosised with type2diabetes mellitus (T2DM) of the First Affiliated Hospital of Zhengzhou University from September the1st,2011to December31,2012. Among them, there are118males with mean age of44.04±7.47years old and102females with mean age of45.88±4.58years old. The diagnosis of the T2DM is correspond to diagnostic criteria made by Word Health Organization (WHO) in1999. Collect60persons with normal glucose tolerance(NGT), among them, there are30male patients with mean age of45.12±6.36years old and30female patients with mean age of44.07±5.58years old. Some cases who are heavy smokers, heavy drinkers, regular drinkers of coffee, suffered from these below diseases:liver and kidney disfunction, cancer, rheumatoid arthritis and endocrinology disease (such as thyroid malfunction, parathyroid malfunction, adrenal cortex malfunction, abnormal of growth hormon and so on), in recent one year have taken medications (like diphosphonate,25(OH) vitD3, calcium supplements, sex hormone, glucocoticoid, diuretic and so on) which affect bone metabolism, who suffered from fracture in the recent one year and people who are often in bed are not included.2. Biochemical measurements After an overnight fasting of12hours, blood samples were collected in the morning under the condition of no stress. Fasting blood glucose was determined by glucose oxidase. The fasting C-peptide(FCP), BGP, β-CTx, P1NP, estradiol(E2), testosterone(T) were measured by electric-chemical-light immunoassay. Hemoglobin A1c(HbAlc) was determined by high performance liquid chromatography. TG and TC were measured by Automatic biochemical analyzer produced by the company Toshiba. Height and weight were measured by the designated personnel, calculating BMI=weigh(kg)/height(m)2, used OGTT and C-peptide release to caculate HOMA-β=270xFCP/0.333/(FBG-3.5), HOMA-CR=1.5+FBGxFCP/(2.8x0.333), CAuc=0.25Comin+0.5C30min+0.75C60min+C120min+0.5C180min, measuring unit of FCP is ng/mL and mmol/L for FBG.3. Statistical methods SPSS15.0statistical software was used to analyze data. All continuous variables of the normal distribution were showed with mean±standard deviation (X±S). After homogeneity of variance test and normality test, independent sample t test was used to compare two arrays of data. Pearson’s correlation coefficient were used in univariate analyses, multiple linear regression analysis to study the relationship between the parameters of bone metabolism and other factors. If P<0.05, there’s statistical significance.Results1.Serum BGP level in diabetes was significantly lower than in the NGT group (P<0.05), but the differences of P1NP andβ-CTx between the two groups were not obvious (P>0.05).2. There were no obvious differences of the serum level of BGP, PINP and β-CTx between males and premenopausal females in the diabetes mellitus (P>0.05).3.Serum BGP level in the type2diabetes mellitus was negatively correlated with HOMA-CR, FBG, HbAlc and BMI (P<0.05), positively correlated with HOMA-β, CAUC(P<0.05), but had no correlation with TC and TG (P>0.05)。4.Serum P1NP and β-CTx have no correlation with FBG, HbAlc, HOMA-CR, HOMA-β, CAUC, TC, TG and BMI (P>0.05)。5.Multivariate analysis showed that HOMA-β,HOMA-CR and HbAlc were independent factors associated with BGP, and BGP was also an independent factor associated with islet cell function and insulin resistance.Conclusions1. Serum BGP level in diabetes was significantly lower than in the NGT group, but the differences of P1NP and β,-CTx between the two groups were not obvious.2. There is no obvious differences of the makers of bone metabolism between males and premenopausal females in the diabetes mellitus.3. Bone acts as an endocrine organ that secrets osteocacin that can stimulate the secretion of insulin, increase insulin sensitivity and improve glucose tolerance, acting on the development of diabetes mellitus.