Osteocalcin and measures of adiposity: a systematic review and meta-analysis of observational studies

Healthy eating index and bone health markers in adults with metabolically healthy and unhealthy obese phenotypes

Background

The Healthy Eating Index (HEI) estimates the diet quality, and low HEI scores are associated with adverse bone outcomes. However, the relationship between HEI scores and bone health in individuals who are obese but otherwise healthy or obese with comorbidities remains unclear.

Objective

We aimed to evaluate the association of HEI scores with bone mineral density (BMD), bone regulating hormones and bone turnover markers in individuals with metabolically healthy obese (MHO) and metabolically unhealthy obese (MUO) phenotypes.

Methods

This was a cross-sectional analysis of 122 adults who were overweight or obese. A questionnaire was completed to obtain demographic data. Body composition and BMD were assessed by a Dual Energy X-Ray Absorptiometry (DXA) exam. The HEI scores and dietary components were calculated using a 24-h dietary recall. Blood samples were collected for the analysis of serum 25-hydroxyvitamin D (s25OHD), total osteocalcin (OC), parathyroid hormone (PTH), and C-terminal telopeptide (CTx) concentrations. The MHO and MUO phenotypes were classified according to the absence or presence of metabolic abnormalities.

Results

The sample mean age was 37.91 ± 12.66 years, 50.8% were men, mean body mass index (BMI) was 30.01 ± 4.63 kg/m2, and 45.9% were classified as the MUO phenotype. The mean HEI scores were 54.42 ± 16.25 and 61.48% had low-diet quality. HEI scores were positively associated with s25OHD in the MUO phenotype group (β = 0.194, 95%CI = 0.038-0.350, p = 0.016). Certain dietary score components, such as fruits, seafood and plant protein, added sugars, whole grains, and fatty acids were also associated with bone health markers. However, HEI scores were not associated with BMD measures, neither with other bone regulating hormones and turnover markers.

Conclusion

There was a positive association between HEI scores and s25OHD in adults who were overweight or obese with MUO phenotype. Additionally, the adequate consumption of specific food groups may benefit bone mass and metabolism. These results emphasize the importance of lifestyle interventions encouraging healthy eating habits to prevent s25OHD deficiency, poor bone health, and cardiometabolic complications.

Osteocalcin levels decrease during the treatment of an acute depressive episode

OBJECTIVES

Osteocalcin is a protein secreted by osteoblasts with a versatile endocrine role. Several domains in which it plays a role-stress response, monoamine synthesis, and cognitive functioning-are implicated also in the pathophysiology of major depressive disorder. In search of possible objective biomarkers of depression, the aim of the study was to assess the relationship between osteocalcin and depressive symptoms during the treatment of depressive episode.

METHODS

The study included female inpatients with at least moderate depressive episode. In these patients, depression severity was measured using the Montgomery-Åsberg Depression Rating Scale (MADRS), and osteocalcin levels were assessed before the stabilization of antidepressive treatment and after 6 weeks. Relationships between osteocalcin levels and symptoms were analyzed with mixed-effect and linear models, taking into account age, menopausal status, and body mass index.

RESULTS

In 11 out of 13 enrolled inpatients, osteocalcin levels decreased during the first 6 weeks of treatment; this decrease was significant according to the mixed-effects model (t = -2.345, p = 0.019). According to the linear model, this decrease was significantly associated with reduction in depressive symptom severity (t = 2.673, p = 0.028). Osteocalcin was not associated with initial depressive symptom severity, and initial osteocalcin levels did not predict response to treatment. Limitations of the study include low sample size and inclusion of both pre- and postmenopausal women of various ages.

CONCLUSIONS

This preliminary study suggests that osteocalcin may be a candidate biomarker of antidepressive treatment response and that this topic warrants further investigation.

Pattern of Adiponectin, Osteocalcin, Irisin, FGF-21, and MCP-1 According to the Body Size Phenotype: Could They Be Markers of Metabolic Health in Mexican-Mestizo Middle-Aged Women?

Variations in levels of some adipokines, myokines, osteokines, hepatokines and inflammatory cytokines contribute to abnormal glucose and lipid metabolism. The aim of this study was to determine the pattern of adiponectin, osteocalcin (OCN), irisin, FGF-21, and MCP-1 according to the body size phenotype of middle-aged women, and their associations with BMI, visceral adipose tissue (VAT), and HOMA-IR. A cross-sectional study in 265 women aged from 40 to 65 years was performed. The biochemical characteristics were evaluated in metabolically healthy normal weight, metabolically unhealthy normal weight, metabolically healthy obese, and metabolically unhealthy obese women. There was an association of OCN with BMI (r = -0.107; p = 0.047); adiponectin with BMI (r = -0.217; p = 0.001), insulin (r = -0.415; p = 0.0001), HOMA-IR (r = -0.429; p = 0.0001), and VAT (r = -0.134; p = 0.025); irisin with BMI (r = 0.604; p = 0.001), insulin (r = 0.446; p = 0.0001), HOMA-IR (r = 0.452; p = 0.0001), and VAT (r = 0.645; p = 0.0001); FGF-21 with insulin (r = -0.337; p= 0.030) and HOMA-IR (r = -0.341; p = 0.03); and MCP-1 with BMI (r = 0.481; p = 0.0001), VAT (r = 0.497; p = 0.001), insulin (r = 0.298; p= 0.001), and HOMA-IR (r = 0.255; p = 0.004). A multivariate analysis showed that an elevation of OCN (OR 1.4 (_95%CI 1.06-1.81)) and a reduction of adiponectin (OR 0.9 (0.84-0.96)) were associated factors for a metabolic unhealthy phenotype in normal weight participants. Likewise, higher irisin (OR 1.007 (1.003-1.011)) and MCP-1 (1.044 (1.008-1.083)) were risk factors for a metabolic unhealthy phenotype in woman with obesity. OCN, adiponectin, irisin, FGF-21, and MCP-1 are associated with some metabolic parameters such as BMI, HOMA-IR, and VAT, and could be possible biomarkers of an unhealthy metabolic phenotype in middle-aged women.

Early identification of metabolic syndrome risk: A review of reviews and proposal for defining pre-metabolic syndrome status

AIMS

a) To analyze the relationship of known and emerging biomarkers/indicators for early risk identification of cardiometabolic health risk; b) to identify early risk markers to be used in both clinical and nonclinical settings; and c) to propose a definition of early risk identification in terms of pre-metabolic syndrome (PreMetSyn).

DATA SYNTHESIS

Pubmed/Medline, Web of Science, Embase, and Cochrane were searched for Systematic Reviews and Meta-analysis. Selected studies were evaluated, and relevant data were extracted and synthesized.

CONCLUSIONS

Serum uric acid is a good predictive biomarker of metabolic syndrome (MetSyn) and has been associated with non-alcoholic liver fat disease (NAFLD) and type 2 diabetes. NAFLD emerges as an early risk indicator of PreMetSyn by itself. Muscle strength should also be included as an early risk marker of cardiometabolic health. High serum triglycerides and waist circumference confirm their predictive value regarding MetSyn. Indicators related to an inflammatory/pro-inflammatory status usually linked to MetSyn showed limited evidence as robust biomarkers for PreMetSyn. Authors suggest defining PreMetSyn related to cardiometabolic risk. It is also necessary to determine how close people are to the cut-off point of MetSyn components, including emerging indicators proposed by our review. Some biomarkers could be used as indicators of PreMetSyn, before any of the MetSyn components appear, allowing early health interventions to prevent its development. Defining a PreMetSyn status might consider both emerging indicators and those variables already included in the definition of MetSyn. New indicators should be considered to create a new risk score specifically meant for PreMetSyn.

Associations of Osteocalcin Forms With Metabolic Syndrome and Its Individual Components in Older Men: The Health In Men Study

CONTEXT

The osteoblast-derived polypeptide, osteocalcin (OC), has been associated with lower risk of type 2 diabetes and metabolic syndrome (MetS) in several epidemiological studies. Animal studies have indicated the undercarboxylated form of OC (ucOC) drives its association with metabolic outcomes.

OBJECTIVE

We compared associations of ucOC and carboxylated OC (cOC) with MetS and its components in older men.

METHODS

A cross-sectional analysis of 2575 men aged ≥70 years and older resident in Perth, Western Australia. ucOC was assayed using a hydroxyapatite-binding method, and cOC calculated by subtracting ucOC from total OC. Main outcome measures were MetS and its components.

RESULTS

Both lower serum ucOC and cOC levels, and the proportion of cOC (%cOC) were associated with less favorable metabolic parameters (higher waist circumference, triglyceride, glucose, blood pressure, and lower high-density lipoprotein cholesterol), whereas inverse associations were found with %ucOC. Men in the lowest quintile of ucOC had higher risk of MetS compared to men in the highest quintile (Q1 ≤ 7.7 vs Q5 > 13.8 ng/mL; OR = 2.4; 95% CI, 1.8-3.2). Men in the lowest quintile of cOC had higher risk of MetS compared to those in the highest quintile (≤ 5.8 vs > 13.0 ng/mL; OR = 2.4; 95% CI, 1.8-3.2).

CONCLUSION

Lower concentrations of serum ucOC or cOC were associated with less favorable metabolic parameters and a higher risk of MetS. In contrast, a lower proportion of ucOC was associated with better metabolic parameters and lower MetS risk. Further research is warranted to determine whether ucOC and cOC are suitable biomarkers for cardiometabolic risk in men.

Circulating osteocalcin levels were not significantly associated with the risk of incident type 2 diabetes mellitus in elderly Japanese men: The Fujiwara-kyo Osteoporosis Risk in Men (FORMEN) Cohort Study

INTRODUCTION

Cross-sectional studies have shown that patients with type 2 diabetes mellitus (T2DM) have low circulating levels of osteocalcin (OC) and undercarboxylated OC (ucOC). This longitudinal study aimed to examine whether low OC or ucOC levels at baseline are associated with the risk of incident T2DM.

METHODS

We examined 1700 community-dwelling Japanese men (≥65 years) after excluding those with history of diseases (other than T2DM) or medications that affect bone and glucose metabolism. T2DM was defined as fasting plasma glucose (FPG) ≥126 mg/dl or glycated hemoglobin A_1c (HbA1c) ≥6.5%. Participants without prevalent T2DM at baseline were invited to follow-up surveys 5 and 10 years after baseline.

RESULTS

Among the participants, 309 with prevalent T2DM showed significantly lower serum OC and ucOC levels at baseline than those without. After excluding these participants, 46 and 57 participants with incident T2DM were identified in the first and second follow-up surveys, respectively. These participants did not show significantly different OC and ucOC levels at baseline relative to those without T2DM, although their FPG and HbA1c levels at baseline were significantly higher compared to those without incident T2DM. Increase in glycemic indices preceded decrease in OC and ucOC levels. OC and ucOC levels at baseline were not significantly associated with the risk of incident T2DM identified in the follow-up surveys.

CONCLUSIONS

OC and ucOC levels at baseline were not significantly associated with the risk of incident T2DM. Our results do not support the findings of animal studies that ucOC is a hormone regulating glucose metabolism.

Change in Circulating Undercarboxylated Osteocalcin (ucOCN) Is Associated With Fat Accumulation in HIV-Seropositive Women

BACKGROUND

Bone mineral density loss and fat accumulation are common in people living with HIV. The bone-derived hormone, undercarboxylated osteocalcin (ucOCN) regulates fat metabolism. We investigated the relationship between ucOCN change and body fat change among perimenopausal/postmenopausal HIV-seronegative and HIV-seropositive women on long-term antiretrovirals.

METHODS

Perimenopausal and postmenopausal women enrolled in the Women's Interagency HIV Study MSK substudy underwent trunk and total fat assessment by dual energy x-ray absorptiometry (DXA) at study enrollment (index visit) and again 2 years later. Circulating ucOCN and cOCN were also measured at the index and 2-year visits. The correlation between the 2-year change in ucOCN and cOCN and change in trunk and total fat was assessed as a function of HIV serostatus using linear regression modeling. Multivariate linear regression assessed the association between ucOCN and cOCN change and total and trunk fat change after adjusting for sociodemographic variables. Linear regression models restricted to HIV-seropositive women were performed to examine the contributions of HIV-specific factors (index CD4 count, viral load, and combined antiretroviral therapy use) on the associations.

RESULTS

Increased ucOCN over the 2-year follow-up was associated with less trunk and total fat accumulation in models adjusting for HIV serostatus and participants sociodemographics, whereas there was no association with cOCN and the fat parameters. None of the HIV-specific factors evaluated influenced the association between ucOCN and fat parameters.

CONCLUSION

The current study suggests that increases in ucOCN are associated with decreased fat accumulation in HIV-seronegative and HIV-seropositive postmenopausal women on long-term antiretroviral therapy.