RELATIONSHIP BETWEEN BONE TURNOVER MARKERS ANDLIPIDS IN PATIENTS WITH DYSLIPIDEMIA

Rima Piličiauskienė1, Vidmantas Alekna1,2, Marija Tamulaitienė1,3

1Vilnius University Faculty of Medicine; 2 State Research Institute Centre for Innovative Medicine; 3 National Osteoporosis Center Vilnius, Lithuania

OBJECTIVEThe aim of this study was to evaluate association of bone turnover markers with different lipids in dyslipidemia.

CONCLUSIONTriglycerides negatively associated with biochemical markers of bone formation and resorption if triglycerides level is normal, and high LDL correlated positively with bone re-sorption marker in subjects with dyslipidemia.

BACKGROUNDStudies, which evaluates relation of biochemical markers and cholesterol is limited

and in addition, the results are controversial. Although some studies have found links between indicators of bone metabolism and blood lipid rate, but the results are con-

tradictory, because found association was between not the same lipids and in different markers of bone turnover [1- 3]. Therefore, it remains unclear whether dyslipidemia associated with bone metabolism.

MATERIAL AND METHODSIt was a cross-sectional study on subjects with dyslipidemia aged 60-90 years. Study

was approved by the Regional Biomedical Research Ethics Committee and performed in the National Osteoporosis Center (Vilnius, Lithuania). Exclusion criteria were: frac-ture during the last 12 month, treating of osteoporosis or dyslipidemia. Blood samples were obtained between 9 and 11 am after overnight fasting and serum bone resorption marker C-telopeptide of type I collagen crosslink (s-CTX-I), type I procollagen amino-terminal propeptide (PINP) and parathyroid hormone (PTH) were measured by au-tomated immunoassay (Cobas e 411, Roche Diagnostic). Analyzes of total cholesterol,

high-density lipoproteins (HDL), triglycerides and low-density lipoproteins (LDL) were performed fully automated by an enzymatic method. Dyslipidemia groups of each lipid were composed according to European guidelines on cardiovascular disease prevention of the European Society of Cardiology (2007), and dyslipidemia was diagnosed when total cholesterol > 5 mmol/l , LDL > 3 mmol/l, and triglycerides > 1.7 mmol/l, HDL for men < 1.2 mmol/l and for women < 1.4 was found. Statistical analysis was performed using SPSS for Windows software version 18.0.

ACNOWLEDGMENTSWe thank the National Osteoporosis Center workers Dr. Elvyra Stapčinskienė and Edita Merkeliūnienė for valuable assistance in this study and PG Asta Mastavičiūtė, PG Vaidilė Strazdienė for their help during this study.

REFERENCES:1. Saghafi H, Hossein-nezhad A, Rahmani M, et al. Relationship between Lipid Profile and Bone Turnover in Pre and Postmenopausal Women. Iranian J Publ Health. 2008; 1: 23–29.2. Wood AD, Hardcastle AD, Duthie GG, et al. Relationship between serum lipids and markers of bone health in post-menopausal women. Proceedings of the Nutrition Society. 2010; 69: 123.3. Kanazawa I, Yamaguchi T, Sugimoto T. Relationship between bone biochemical markers versus gliucose/lipid metabolism and atherosclerosis; a longitudinal study in type 2 diabetes mellitus. Diabetes Res Clin Pract. 2011; 92(3): 393–9.

We have found that higher total cholesterol (6.25 ± 0.98 mmol/l) was in 211 (85.8 %) persons, higher LDL (4.11 ± 0.87 mmol/l) – in 203 (82.5 %), higher triglycerides (2.33 ± 0.63 mmol/l) – in 53 (21.5 %) and lower HDL (1.14 ± 0.16 mmol/l) in 76 (29.7 %) sub-jects. We have analyzed the correlation of bone resorption and formation markers with serum lipids and the results are summarized in Table 2.

There were no significant differences in age and bone markers between genders. Total cholesterol, HDL and LDL were statistically significantly lower in men than in women.

Week negative Spearman correlation was found between triglycerides and s-CTX-I and between triglycerides and PINP in the group of normal triglycerides. Statistically significant correlation of LDL with s-CTX-I was found in group with LDL-dyslipidemia.

RESULTSData of 246 participants were analyzed, of them 99 were men and 147 women. Table

1 shows the basic characteristics of subjects.

Table 1. Baseline characteristics (mean ± SD)

p value calculated using Mann-Whitney U test. SD – standard deviation; HDL – high density lipoprotein cho-lesterol; LDL – low density lipoprotein cholesterol; s-CTX-I – C-terminal cross-linking telopeptide of type I col-

lagen; PINP – procollagen type I N propeptide; PTH - parathyroid hormone.

Parameters Men (n = 99) Women (n = 147) p

Age, years 70.48 ± 7.32 72.48 ± 7.59 0.128

Total cholesterol, mmol/l 5.67 ± 1.15 6.19 ± 1.11 <0.0001

HDL, mmol/l 1.4 ± 0.38 1.63 ± 0.43 <0.0001

LDL, mmol/l 3.67 ± 0.98 3.98 ± 0.95 <0.005

Triglycerides, mmol/l 1.39 ± 0.66 1.39 ± 0.6 0.712

s-CTX-I, ng/ml 0.435 ± 0.205 0.476 ± 0.211 0.105

PINP, ng/ml 53.78 ± 29.02 55.64 ± 21.19 0.146

Vitamin D, ng/ml 17.2 ± 10.91 16.55 ± 8.32 0.934

PTH, pg/ml 50.2 ± 20.43 51.95 ± 21.94 0.648

Table 2. Spearman correlation of bone turnover parameters with lipids

HDL - high density lipoprotein cholesterol; LDL - low density lipoprotein cholesterol; s-CTX-I - C-terminal cross-linking telopeptide of type I collagen; PINP - procollagen type I N propeptide.

Serum lipidss-CTX-I PINP

r r r rTotal cholesterol

normal 0.07 0.705 -0.08 0.666higher 0.05 0.432 -0.03 0.691

HDLnormal 0.08 0.283 0.12 0.108lower -0.04 0.759 0.001 0.995

LDLnormal 0.14 0.360 0.11 0.465higher 0.15 0.038 0.02 0.808

LDLnormal -0.2 0.006 -0.2 0.008higher -0.19 0.163 -0.16 0.265

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