The positive association of total protein intake with femoral neck strength (KNHANES IV)

Sprinting performance correlates with composite indices of femoral neck strength in middle-aged active men

The aim of the current study was to explore the relationships between 20-meter sprinting time and composite indices of femoral neck strength (compression strength index (CSI), bending strength index (BSI) and impact strength index (ISI)) in a group of middle-aged active men. 50 middle-aged active men voluntarily participated in this study. Their mean age was 45 ± 8.6 years. Body composition, total hip bone mineral density (TH BMD) and femoral neck bone mineral density (FN BMD) were evaluated by DXA. Sprinting time was negatively correlated to CSI (r = -0.52; p < 0.001), BSI (r = -0.43; p < 0.01) and ISI (r = -0.47; p < 0.001). The significant correlations between sprinting time and composite indices of femoral neck strength (CSI, BSI and ISI) remained significant after controlling for body weight, age and maximum oxygen consumption using multiple linear regressions. In conclusion, the current study suggests that sprinting performance (m/sec) is a positive determinant of CSI, BSI and ISI in middle-aged men.

Association of geriatric nutritional risk index with bone mineral density and osteoporosis in postmenopausal elderly women with T2DM

BACKGROUND AND OBJECTIVES

To investigate the relationship between geriatric nutritional risk index (GNRI) and osteoporosis (OP) in postmenopausal elderly women with type 2 diabetes mellitus (T2DM).

METHODS AND STUDY DESIGN

A total of 141 postmenopausal elderly women with T2DM was divided into OP and normal bone mineral density (BMD) groups, the differences in GRNI levels between the two groups were compared. According to the tertile levels of GRNI, T2DM were divided into three groups (T1, T2, T3 groups), and the differences in OP prevalence and levels of BMD among the three groups were compared.

RESULTS

Among postmenopausal elderly women with T2DM, GNRI levels were lower in the OP group compared to the nor-mal BMD group [(103±5.46) vs. (105±5.46), p<0.05)]. With elevated GNRI levels, the BMD levels of femoral, total hip, total body, and lumbar vertebrae (L) were gradually increased, which were higher in the T3 group than in the T1 group (all p< 0.05). GNRI levels were positively correlated with the BMD levels of femoral, spine, total hip, total body, L1, L2, L3, L4, and L1-L4. GNRI was an independent influencing factor for the occurrence of OP (OR=0.887, 95%CI [0.795,0.988]). The ROC curve showed that the GNRI combined with serum ALP and P levels had a high predictive value for OP, with an area under the curve of 0.725 (p<0.01).

CONCLUSIONS

In postmenopausal elderly women with T2DM, GNRI was independently and positively correlated with BMD levels. GNRI may be a predictor development of OP.

Association between macronutrients intake distribution and bone mineral density

BACKGROUND & AIMS

Although it is well known dietary factors are closely correlated with bone health, the association between macronutrients intake distribution and bone mineral density (BMD) is still unclear. The aims of this study were to investigate how macronutrients distribution was correlated with BMD, and to evaluate how the substitution between macronutrients could be associated with BMD.

METHODS

We conducted a cross-sectional study based on data from National Health and Nutrition Examination Survey. Dietary recall method was used to assessed the intake of macronutrients. Macronutrient intake distribution including carbohydrate, protein and fat was calculated as percentages of energy intake from total energy. BMD was converted to T-score and low BMD was defined as T-score less than -1.0. The association between the percentages of energy intake from carbohydrate, protein and fat with T-score and risk of low BMD was evaluated using multivariate regression models. Isocaloric substitution analysis was conducted using the multivariate nutrient density method.

RESULTS

Data form 4447 adults aged 20 years and older who underwent BMD examination were included in this study. Higher percentage of energy intake from carbohydrate was associated with lower T-score (-0.03 [95%CI, -0.05 to -0.01]; P = 0.001) and higher risk of low BMD (1.05 [95%CI, 1.02-1.08]; P = 0.003), while higher percentage of energy intake from protein was associated with higher T-score (0.05 [95%CI, 0.01-0.08]; P = 0.009) and lower odds of low BMD (0.92 [95%CI, 0.87-0.98]; P = 0.007). The percentage of energy intake from fat seemed to be positively correlated with T-score, but the correlation became insignificant after adjusting for metabolism related confounders. Isocaloric substitution analysis showed that only the substitution between carbohydrate and protein was significantly and independently associated with T-score (-0.05 [95%CI, -0.08 to -0.01]; P = 0.01) and the risk of low BMD (1.08 [95%CI, 1.02-1.15]; P = 0.008).

CONCLUSIONS

Based on the results from this study, we hypothesized that a high-protein diet coupled with low carbohydrate intake would be beneficiary for prevention of bone loss in adults. However, randomized clinical trials or longitudinal studies are needed to further assessed our findings.

Rationale and Design for a Higher (Dairy) Protein Weight Loss Intervention That Promotes Muscle Quality and Bone Health in Older Adults with Obesity: A Randomized, Controlled Pilot Study

In contrast to recommendations for young and middle-aged adults, intentional weight loss among older adults remains controversial and is inconsistently advised. Recent research suggests that a higher protein diet can mitigate loss of lean mass during periods of intentional weight loss among older adults with obesity; however, the effects of intentional weight loss on skeletal muscle and bone are not fully understood. The Dairy in the Diet Yields New Approaches for Muscle Optimization (DDYNAMO) trial is a 6-month, randomized, controlled pilot study assessing the effects of combining regular, generous intakes of high quality protein (30 g/meal; primarily from dairy) with caloric restriction (-500kcal/d) and low-intensity resistance exercise (30 min/3 times per week) on muscle quality, muscle composition, bone mineral density in men and women aged ≥60 years with obesity and mild to moderate functional impairment (Short Physical Performance Battery [SPPB] score ≥4 to ≤10). Participants will be re-assessed at 18 months to evaluate weight maintenance, bone mineral density, physical function, and other secondary measures. ClinicalTrials.gov Identifier: NCT02437643.

Influence of Physical Activity Level on Composite Indices of Femoral Neck Strength in a Group of Young Overweight Men

The aim of the present study was to explore the influence of physical activity level on composite indices of femoral neck strength (compression strength index [CSI], bending strength index, and impact strength index) in a group of young overweight men. To do so, we compared composite indices of femoral neck strength in active overweight men and insufficiently active overweight men. They were divided into 2 groups based on their physical activity level: 70 active overweight men (engaging in more than 150 minutes of physical activity per week; 8.7 ± 4.8 h/wk) and 26 insufficiently active overweight men (engaging in less than 150 minutes of physical activity per week; 1.2 ± 0.7 h/wk). Height (m) and weight (kg) were measured, and body mass index (kg/m²) was calculated. Bone mineral density was measured by dual-energy X-ray absorptiometry at whole body, lumbar spine, total hip, and femoral neck. Body weight, lean mass, fat mass, and body mass index were not significantly different between the 2 groups. CSI, bending strength index, and impact strength index were significantly higher in active overweight men compared to insufficiently active overweight men. After adjustment for age, physical activity (h/wk) and lean mass, only CSI remained higher in active overweight men compared to insufficiently active overweight men. This study suggests that, in young overweight men, being active (engaging in more than 150 minutes of physical activity per week) is associated with greater composite indices of femoral neck strength. To our knowledge, this is the first study that finds a significant difference regarding composite indices of femoral neck strength between 2 groups of young overweight men with different levels of physical activity.

Young cancer survivors have lower bone mineral density compared with healthy controls: a nationwide population-based study in Korea

Direct effects of cancer cells and various cancer treatments can cause bone loss in cancer survivors. The aim of this study was to assess the risk of bone loss in Korean cancer survivors, and the relationship between body composition and bone mineral density (BMD). We hypothesized that cancer survivors would have lower BMD than healthy people, and increased muscle mass has a protective effect on BMD. We measured BMD and body composition in 259 cancer survivors (99 men and 160 women). Subjects were selected from the Korean National Health and Nutrition Survey conducted from 2008 to 2011. Body composition and BMD were measured by dual-energy X-ray absorptiometry. We examined the linear trend of lumbar BMD according to tertiles of lean mass (LM) and fat mass (FM) by linear regression, adjusting for age, alcohol consumption, smoking, exercise, 25-hydroxyvitamin D, height, protein intake, and menopausal status. Cancer survivors under 50 years of age had lower lumbar BMD compared with healthy controls (0.93 ± 0.04 g/cm² vs. 1.02 ± 0.01 g/cm², p = 0.032 in males; 0.95 ± 0.02 g/cm² vs. 0.98 ± 0.01 g/cm², p = 0.015 in females). Lumbar BMD significantly increased from the lowest to highest tertiles of LM in male (p for trend < 0.001) and marginally significantly increased in female survivors (p for trend = 0.060). In this study of Korean cancer survivors, young survivors were at higher risk of having low lumbar BMD. Higher LM had beneficial effects on BMD in cancer survivors. To prevent osteoporosis and fractures, efforts to increase lean body mass, including bone, are needed for young cancer survivors.

Impact on cardiometabolic risk of a weight loss intervention with higher protein from lean red meat: Combined results of 2 randomized controlled trials in obese middle-aged and older adults

BACKGROUND

The recognized benefits of a higher protein diet on muscle mass and strength in older adults are tempered by concerns of the potentially negative cardiometabolic impact of dietary sources of animal protein.

OBJECTIVE

The aim of this study was to explore the cardiometabolic impact of 2 weight reduction diets: a higher protein diet, providing balanced portions of lean beef and pork throughout the day, vs. a diet following the Recommended Daily Allowance level of protein in obese middle-aged and older adults.

METHODS

Data from Measuring Eating, Activity and Strength: Understanding the Response-Using Protein and Protein Optimization in Women Enables Results-Using Protein were combined for the present analysis. Subjects were randomly assigned to a 6-month weight loss diet (500 kcal deficit) and prescribed a Recommended Daily Allowance level of protein (0.8 g protein/kg BW), control group, or a higher level of protein (1.2 g protein/kg BW), protein group. For the protein group, lean, high-quality protein was evenly distributed between meals or balanced throughout the day (30 g protein/meal). The following cardiometabolic markers were quantified by nuclear magnetic resonance spectroscopy: lipids, lipoproteins, GlycA, trimethylamine-N-oxide, betaine, branched-chain amino acids, and lipoprotein insulin resistance index scores.

RESULTS

In both groups (control [n = 27] and protein [n = 53]), there were significant (P ≤ .05) changes from baseline in weight loss (-6.2% and -7.2%), distance walked (+53.1 and +75.0 meters), and fasting plasma glucose (-7.5 and -6.2 mg/dL), respectively. At endpoint, protein group had significantly (P ≤ .05) lower triglycerides (-17.3 mg/dL), large very-low-density lipoprotein particle concentration (VLDL-P; -1.2 nmol/L), total low-density lipoprotein particle concentration (LDL-P; -67.8 nmol/L), small LDL-P (-59.4 nmol/L) and lipoprotein insulin resistance index (-5.9), whereas control group had significantly (P ≤ .05) lower GlycA (-13.1 μmol/L), total VLDL-P (-7.9 nmol/L), and small VLDL-P (-7.0 nmol/L). Differences between groups were observed for small VLDL-P (P = .02) and protein intake (P < .0001).

CONCLUSIONS

These findings suggest that a hypocaloric diet with either traditional (0.8 g/kg BW/d) or higher protein (1.2 g/kg BW/d; predominantly from lean red meat) content improves risk markers of cardiovascular disease and type II diabetes in obese middle-aged and older adults. Both diets were also associated with improved physical function, and neither had an adverse impact on cardiometabolic outcomes.

Dietary protein and bone health across the life-course: an updated systematic review and meta-analysis over 40 years

We undertook a systematic review and meta-analysis of published papers assessing dietary protein and bone health. We found little benefit of increasing protein intake for bone health in healthy adults but no indication of any detrimental effect, at least within the protein intakes of the populations studied. This systematic review and meta-analysis analysed the relationship between dietary protein and bone health across the life-course. The PubMed database was searched for all relevant human studies from the 1st January 1976 to 22nd January 2016, including all bone outcomes except calcium metabolism. The searches identified 127 papers for inclusion, including 74 correlational studies, 23 fracture or osteoporosis risk studies and 30 supplementation trials. Protein intake accounted for 0-4% of areal BMC and areal BMD variance in adults and 0-14% of areal BMC variance in children and adolescents. However, when confounder adjusted (5 studies) adult lumbar spine and femoral neck BMD associations were not statistically significant. There was no association between protein intake and relative risk (RR) of osteoporotic fractures for total (RR_(random) = 0.94; 0.72 to 1.23, I² = 32%), animal (RR _(random) = 0.98; 0.76 to 1.27, I² = 46%) or vegetable protein (RR _(fixed) = 0.97 (0.89 to 1.09, I² = 15%). In total protein supplementation studies, pooled effect sizes were not statistically significant for LSBMD (total n = 255, MD_(fixed) = 0.04 g/cm² (0.00 to 0.08, P = 0.07), I² = 0%) or FNBMD (total n = 435, MD_(random) = 0.01 g/cm² (-0.03 to 0.05, P = 0.59), I² = 68%). There appears to be little benefit of increasing protein intake for bone health in healthy adults but there is also clearly no indication of any detrimental effect, at least within the protein intakes of the populations studied (around 0.8-1.3 g/Kg/day). More studies are urgently required on the association between protein intake and bone health in children and adolescents.