Relationship Between Plasma Homocysteine and Bone Density, Lean Mass, Muscle Strength and Physical Function in 1480 Middle-Aged and Older Adults: Data from NHANES

Association Between Homocysteine and All-Cause Mortality Among Osteoarthritis Patients: A Cohort Study from the NHANES Database

This study explored the association between serum Hcy level and the all-cause mortality among osteoarthritis (OA) patients. This cohort study included patients diagnosed as OA from the National Health and Nutrition Examination Survey (NHANES) 1999-2006. Abbott Homocysteine assay, a fully automated fluorescence polarization immunoassay (FPIA) method, was used to measure the level of serum Hcy. Covariates included sociodemographic information, lifestyles, history of diseases and medications were extracted from the database. The weighted univariate, multivariate Cox proportional hazard models and restricted cubic splines (RCS) were utilized to explore the association between Hcy level and all-cause mortality in OA patients, with hazard ratios (HRs) and 95% confidence intervals (CIs). Subgroup analyses based on different age, gender, duration of OA, complications and C-reactive protein (CRP) were further assessed by this association. Totally 1384 OA patients were included in this study, of which 817 (59.03%) died by 31 December 2019. After adjusting all covariates, high Hcy level was associated with the high all-cause mortality among OA patients (HR=1.31, 95%CI: 1.02-1.67), especially in females (HR=1.43, 95%CI: 1.07-1.91), aged >60 years (HR=1.49, 95%CI: 1.14-1.94), duration of OA >10 years (HR=1.40, 95%CI: 1.01-1.95), with the history of hypertension (HR=1.37, 95%CI: 1.03-1.80), without the history of diabetes (HR=1.36, 95%CI: 1.01-1.82) or CRP >0.29 mg/l (HR=1.51, 95%CI: 1.04-2.19). High serum Hcy level was associated with high risk of all-cause mortality in OA patients. Our results suggest that serum Hcy is a promising biomarker for the prognosis of OA patients.

The Relevance of Plant-Based Diets and Micronutrient Supplementation for Body Composition: Data from the VeggieNutri Cross-Sectional Study

OBJECTIVES

This study aimed to compare the anthropometry and body composition of vegetarian and omnivorous adults living in Portugal, while exploring nutritional and health parameters underlying observed differences.

METHODS

425 omnivorous (OMNI), lacto-ovo-vegetarian (LOV), or vegan (VEG) healthy adults were recruited. Anthropometry was measured, and bioelectrical impedance analysis was performed. Participants answered food frequency, sociodemographic, and lifestyle questionnaires. Serum iron, ferritin, and CRP were quantified by spectrophotometry, and serum B12 vitamin and homocysteine were quantified by chemiluminescent microparticle immunoassay.

RESULTS

Total protein intake significantly decreased with increasing strictness of vegetarian habits (median (P25; P75) in g/day: 98.6 (79.5; 123.1), 90.4 (65.9; 121.0), and 87.6 (59.8; 118.5) for OMNI, LOV and VEG, respectively; p = 0.020), and carbohydrate intake was the highest in LOV (median (P25; P75) in g/day: 231.5 (178.4; 287.9), 283.9 (227.3; 342.6), and 263.0 (222.0; 348.3) for OMNI, LOV and VEG, respectively; p = 0.001). VEG were the main users of B12 vitamin (93% in VEG vs. 17% in OMNI and 59% in LOV, p = 0.001), and LOV were the main users of iron supplements (29% in LOV vs. 14% in OMNI and 13% in VEG, p = 0.042), respectively. Blood levels of B12 vitamin correlated negatively with blood homocysteine (rs = -0.386, p < 0.001) and positively with % muscle mass (rs = 0.136, p = 0.005). Participants using iron supplements presented higher C-reactive protein (CRP) (p = 0.014) and they had lower % MM (p = 0.003). Finally, when compared to being OMNI, being LOV independently associated with: (a) having +4.8% (p = 0.002) of fat mass, which could be due to higher carbohydrate intake, and (b) having -2.2% (p = 0.043) of muscle mass. Our data suggest that the association between diet and muscle mass could be attenuated in VEG due to B12 supplementation and/or aggravated in LOV due to iron supplementation-associated inflammation.

Association of Serum Homocysteine With Peripheral Arterial Disease in Patients Without Diabetes: A Study Based on National Health and Nutrition Examination Survey Database

This study aimed to investigate the association of serum homocysteine (Hcy) levels with peripheral arterial disease (PAD) in patients without diabetes on the basis of data from the National Health and Nutrition Examination Survey. The study used data from 3 survey cycles (1999 to 2004) in the National Health and Nutrition Examination Survey database as the research dataset. Serum Hcy levels were considered an independent variable, whereas PAD was a dependent variable. Weighted logistic regression and restricted cubic spline methods were used to explore the relation between Hcy level and PAD risk in patients without diabetes. A total of 4,819 samples were included. In the weighted logistics regression model, a significant positive association was observed between Hcy levels and the risk of PAD (odds ratio >1, p <0.05). Subgroup analysis results indicated a particularly significant association between Hcy levels and PAD risk in the older population (age ≥60 years), those with a history of smoking, and those without a history of myocardial infarction (all odds ratio >1, p <0.05) (p <0.05). Exploring the nonlinear association between Hcy levels and PAD risk through restricted cubic spline curves revealed an overall significant trend (p allover <0.05). In conclusion, elevated Hcy levels increased the risk of PAD, with a more pronounced effect observed in populations of patients without diabetes, especially in older patients (age ≥60 years), those with smoking history, and those without a history of myocardial infarction.

The Differential Effect of Metformin on Osteocytes, Osteoblasts, and Osteoclasts

PURPOSE OF REVIEW

Metformin is an anti-glycemic agent, which is widely prescribed to diabetes patients. Although its alleged role on bone strength has been reported for some time, this review focuses primarily on the recent mechanistical insights of metformin on osteocytes, osteoblasts, and osteoclasts.

RECENT FINDINGS

Overall, metformin contributed to steering anabolic activity in osteocytes. It caused lower expression in osteocytes of the negative regulators of bone formation sclerostin and DKK1. Likewise, the osteoclastogenesis function of osteoblasts was also skewed towards lower RANKL and higher OPG expressions. Osteoblast lineage cells generally responded to metformin by activating bone formation parameters, such as alkaline phosphatase activity, higher expression of anabolic members of the Wnt pathway, transcription factor Runx2, bone matrix protein proteins, and subsequent mineralization. Metformin affected osteoclast formation and activity in a negative way, reducing the number of multinucleated cells in association with lower expression of typical osteoclast markers and with inhibited resorption. A common denominator studied in all three cell types is its beneficial effect on activating phosphorylated AMP kinase (AMPK) which is associated with the coordination of energy metabolism. Metformin differentially affects bone cells, shifting the balance to more bone formation. Although metformin is a drug prescribed for diabetic patients, the overall bone anabolic effects on osteocytes and osteoblasts and the anti-catabolic effect on osteoclast suggest that metformin could be seen as a promising drug in the bone field.