Role of diet quality in bone health in children and adolescents: a systematic review.

CONTEXT: Poor diet quality and unhealthy dietary patterns have been linked to poor bone health, yet few studies have investigated the role of diet quality in bone health in pediatric populations. OBJECTIVE: This systematic review aims to assess the available evidence on the association between diet quality and bone health markers in children and adolescents. DATA SOURCES: The PubMed, Scopus, and Virtual Health Library databases were searched electronically from October to November 2022, without any restrictions on date or language. The STROBE (Strengthening the Reporting of Observational Studies in Epidemiology) checklist was used to assess the quality of the studies. DATA EXTRACTION: Published observational studies in children and adolescents (ages 2 to 19 years) that investigated the association between diet quality and bone health were eligible for inclusion. Two researchers independently analyzed and selected all articles using the Rayyan app. Initially, 965 papers were identified. A total of 12 observational studies qualified, including 8 cross-sectional and 4 longitudinal studies. The sample comprised 7130 individuals aged 3 to 17.9 years, representing both sexes. Bone health was evaluated by measures of bone mineral density and bone mineral content. DATA ANALYSIS: Seven studies (58.3%) showed significant associations between diet quality and bone health markers, all of which evaluated diet quality by identifying dietary patterns. Diet quality as evaluated by all dietary indexes was not associated with bone health markers. CONCLUSIONS: Adherence to a healthy diet may benefit bone health in children and adolescents. These findings emphasize the importance of developing effective public health policies that encourage healthy eating habits from childhood to preserve bone health. Longitudinal research using a specific tool to assess diet quality in relation to bone health is warranted. Future studies should also measure bone-regulating hormones and markers of bone turnover. SYSTEMATIC REVIEW REGISTRATION: PROSPERO registration no. CRD42022368610.

Combined vitamin D and magnesium supplementation does not influence markers of bone turnover or glycemic control: A randomized controlled clinical trial.

High-dose vitamin D supplementation can increase total osteocalcin concentrations that may reduce insulin resistance in individuals at risk for prediabetes or diabetes mellitus. Magnesium is a cofactor in vitamin D metabolism and activation. The purpose of this study was to determine the combined effect of vitamin D and magnesium supplementation on total osteocalcin concentrations, glycemic indices, and other bone turnover markers after a 12-week intervention in individuals who were overweight and obese, but otherwise healthy. We hypothesized that combined supplementation would improve serum total osteocalcin concentrations and glycemic indices more than vitamin D supplementation alone or a placebo. A total of 78 women and men completed this intervention in 3 groups: a vitamin D and magnesium group (1000 IU vitamin D3 and 360 mg magnesium glycinate), a vitamin D group (1000 IU vitamin D3), and a placebo group. Despite a significant increase in serum 25-hydroxyvitamin D concentrations in the vitamin D and magnesium group compared with the placebo group (difference = 5.63; CI, -10.0 to -1.21; P = .001) post-intervention, there were no differences in serum concentrations of total osteocalcin, glucose, insulin, and adiponectin or the homeostatic model assessment of insulin resistance (HOMA-IR) among groups (P > .05 for all). Additionally, total osteocalcin (ß = -0.310, P = .081), bone-specific alkaline phosphatase (ß = 0.004, P = .986), and C-terminal cross-linked telopeptide (ß = 0.426, P = .057), were not significant predictors of HOMA-IR after the intervention. Combined supplementation was not associated with short-term improvements in glycemic indices or bone turnover markers in participants who were overweight and obese in our study. This trial was registered at clinicaltrials.gov (NCT03134417).

Vitamin d deficiency and metabolic syndrome: The joint effect on cardiovascular and all-cause mortality in the United States adults.

BACKGROUND: The long-term impact of vitamin D deficiency and metabolic syndrome (MetS) on cardiovascular disease (CVD) and all-cause mortality are still a matter of debate. AIM: To test the hypotheses that lower serum 25 hydroxyvitamin D [25(OH)D] concentrations (a marker of vitamin D level) and MetS have a long-term impact on the risk of CVD and all-cause mortality, and individuals with vitamin D deficiency can be identified by multiple factors. METHODS: A sample of 9094 adults, 20 to 90 years of age, who participated in the Third National Health and Nutrition Examination Survey (NHANES III, 1988 to 1994) were followed through December 2015 was analyzed. The associations of serum 25(OH)D concentrations and MetS with CVD and all-cause mortality were analyzed longitudinally using Cox regression models. Classification and regression tree (CART) for machine learning was applied to classify individuals with vitamin D deficiency. RESULTS: Of 9094 participants, 30% had serum 25(OH)D concentrations < 20 ng/mL (defined as vitamin D deficiency), 39% had serum 25(OH)D concentrations between 20 to 29 ng/mL (insufficiency), and 31% had serum 25(OH)D concentrations ≥30 ng/mL (sufficiency). Prevalence of MetS was 28.4%. During a mean of 18 years follow-up, vitamin D deficiency and MetS were significantly associated with increased risk of CVD and all-cause mortality. Subjects with both vitamin D deficiency and MetS had the highest risk of CVD mortality (HR = 1.77, 95%CI: 1.22-2.58) and all-cause mortality (HR = 1.62, 95%CI: 1.26-2.09), followed by those with both vitamin D insufficiency and MetS for CVD mortality (HR = 1.59, 95%CI: 1.12-2.24), and all-cause mortality (HR = 1.41, 95%CI: 1.08-1.85). Meanwhile, vitamin D sufficiency significantly decreased the risk of CVD and all-cause mortality for those who even had MetS. Among the total study sample, CART analysis suggests that being non-Hispanic Black, having lower serum folate level, and being female were the first three predictors for those with serum 25(OH)D deficiency. CONCLUSION: Vitamin D deficiency and MetS were significantly associated with increased risk of CVD and all-cause mortality. There was a significant joint effect of vitamin D deficiency and MetS on the risk of mortality. Findings of the CART analysis may be useful to identify individuals positioned to benefit from interventions to reduce the risk of CVD and all-cause mortality.

The effect of combined magnesium and vitamin D supplementation on vitamin D status, systemic inflammation, and blood pressure: A randomized double-blinded controlled trial.

OBJECTIVE: Poor vitamin D and magnesium status is observed in individuals who are overweight and obese (Owt/Ob) and is often associated with a heightened risk of cardiovascular disease. Magnesium is a cofactor that assists vitamin D metabolism. We aimed to determine the efficacy of a combined magnesium and vitamin D regimen compared with vitamin D only on increasing serum 25-hydroxyvitamin D (25OHD) concentrations and the effects of these supplements on cardiometabolic outcomes. METHODS: This 12-week double-blinded randomized controlled trial had three treatment arms: magnesium + vitamin D (MagD; 360 mg magnesium glycinate + 1000 IU vitamin D 3 × daily), vitamin D only (VitD; 1000 IU vitamin D 3 × daily), and placebo. A total of 95 Owt/Ob participants were randomized into one of these three study arms. Anthropometry, dietary intake, concentrations of serum 25OHD, serum parathyroid hormone (PTH), serum inflammatory markers, and blood pressure were obtained at baseline and week 12. RESULTS: The MagD group experienced the greatest increase in serum 25OHD concentrations (6.3 ± 8.36 ng/mL; P < 0.05). There was a decrease in systolic blood pressure (7.5 ± 8.26 mmHg; P < 0.05) for individuals who had a baseline systolic blood pressure of >132 mmHg in the MagD group. There were no statistically significant treatment effects on serum PTH concentrations and markers of inflammation. CONCLUSIONS: A combined MagD treatment may be more effective in increasing serum 25OHD concentrations compared with VitD supplementation alone in Owt/Ob individuals.

Higher protein intake during caloric restriction improves diet quality and attenuates loss of lean body mass.

OBJECTIVE: Higher protein intake during weight loss is associated with better health outcomes, but whether this is because of improved diet quality is not known. The purpose of this study was to examine how the change in self-selected protein intake during caloric restriction (CR) alters diet quality and lean body mass (LBM). METHODS: In this analysis of pooled data from multiple weight loss trials, 207 adults with overweight or obesity were examined before and during 6 months of CR (approximately 10 food records/person). Body composition was measured by dual-energy x-ray absorptiometry. Diet quality was assessed using the Healthy Eating Index in 2 groups: lower (LP) and higher (HP) protein intake. RESULTS: Participants (mean [SD], 54 [11] years; 29 [4] kg/m2 ) lost 5.0% (5.4%) of weight. Protein intake was 79 (9) g/d (1.0 [0.2] g/kg/d) and 58 (6) g/d (0.8 [0.1] g/kg/d) in the HP and LP groups, respectively (p < 0.05), and there was an attenuated LBM (kilograms) loss in the HP (-0.6% [1.5%]) compared with the LP (-1.2% [1.4%]) group (p < 0.01). The increased Healthy Eating Index score in the HP compared with the LP group was attributed to greater total protein and green vegetable intake and reduced refined grain and added-sugar intake (p < 0.05). CONCLUSIONS: Increasing dietary protein during CR improves diet quality and may be another reason for reduced LBM, but it requires further study.

Changes in Dietary Magnesium Intake and Risk of Type 2 Diabetes Mellitus in Middle School Students: Using Data from the HEALTHY Study.

BACKGROUND: The HEALTHY Study was a multicomponent school-based intervention, designed to prevent type 2 diabetes mellitus (T2DM) in middle-school students. OBJECTIVES: We examined whether the difference in dietary magnesium intake, BMI percentile, and plasma glucose and insulin concentrations from 6th to 8th grade were related in the intervention schools and in the control schools that participated in the HEALTHY Study. METHODS: A total of 2181 ethnically diverse students, from 11.3 to 13.7 y of age, with completed dietary records, BMI percentile, and plasma glucose and insulin concentrations at 6th and 8th grades were included. Dietary magnesium intake was self-reported using the Block Kids FFQ. A hierarchical multiple regression model was used to determine whether the differences in dietary magnesium intake, BMI percentile, and plasma glucose and insulin concentrations from 6th to 8th grades were related, while adjusting for dietary calcium intake and total energy intake. RESULTS: The difference in dietary magnesium intake was significantly related to changes in BMI percentile from 6th to 8th grade in intervention and in control schools [intervention: ß: -0.07; 95% CI: -0.58, -0.02; P = 0.03; R2 (regression coefficient effect size): 0.14; 95% CI for R2: 0.10, 0.17; control: ß: -0.08; 95% CI: -0.63, -0.09; P = 0.01; R2: 0.12; 95% CI for R2: 0.08, 0.15]. The difference in dietary magnesium intake was not related to plasma glucose and insulin concentrations in intervention and in control schools. CONCLUSIONS: We conclude that a multicomponent intervention was associated with reduced risk of T2DM, and that this association may be modulated, in part, by magnesium. The differences in dietary magnesium intake from 6th to 8th grade were negatively related to changes in BMI percentile among middle-school students.

Dietary magnesium intake in relation to body mass index and glycemic indices in middle school students from the HEALTHY Study.

BACKGROUND: Data on dietary magnesium intake on the risk of type 2 diabetes mellitus (T2DM) among children and adolescents is limited. AIM: We examined whether dietary magnesium intake was related to body mass index (BMI) percentile, and glycemic indices at baseline and at end of the HEALTHY Study for both intervention and control schools. The HEALTHY Study was a multi-component, school-based intervention, to prevent T2DM in children and adolescents from 6th to 8th grades. METHODS: A secondary data analyses of 2181 ethnically diverse students with completed dietary records, BMI percentile, and plasma insulin and glucose concentrations at baseline (6th grade) and end of study (8th grade) were included from the HEALTHY Study. Dietary magnesium intake was self-reported using the Block Kids Food Frequency Questionnaire. A hierarchical multiple regression model was used to determine the relationships between dietary magnesium intake, BMI percentile, and glycemic indices at baseline and end of the HEALTHY Study, adjusting for magnesium intake from supplements, total energy intake, and fitness level. RESULTS: Dietary magnesium intake was related to BMI percentile at baseline and at end of the HEATHY Study (ß = -0.05, 95% CI = -0.02 to 0, p = 0.04; ß = -0.06, 95% CI = -0.02 to -0.003, p = 0.004); R 2 [regression coefficient effect size] = 0.03; R 2 = 0.06). Dietary magnesium intake was not related to plasma insulin and glucose concentrations at baseline and end of the HEALTHY Study. CONCLUSION: Dietary magnesium intake was inversely related to BMI percentile among middle school students from the HEALTHY Study. Research is required to evaluate the dose-response relationship between fruit and vegetable consumption (good sources of magnesium) and risk of T2DM in children and adolescents. This relationship also needs to be explored among different BMI categories.

The implications of vitamin D deficiency on COVID-19 for at-risk populations.

Novel coronavirus disease 2019 (COVID-19) has spread to > 10 000 000 individuals in a short time. With no pharmacological agents successfully implemented to control the outbreak, the use of less invasive nonpharmacological agents, such as vitamin D, are increasingly being studied. This purpose of this article is to determine the current knowledge about the risk of COVID-19 development for populations at risk for vitamin D deficiency, including individuals living with overweight and obesity, those of older age, and racial or ethnic minorities. Despite the documented impact of vitamin D on viral disease prevention, many subgroups at risk for contracting COVID-19 are also known to have increased rates of vitamin D deficiency. Because vitamin D is most commonly obtained from sunlight, when interpreted alongside the stay-at-home orders, the importance of identifying safe approaches to obtain sufficient vitamin D is apparent. Furthermore, elucidating the cause-and-effect relationship between vitamin D and COVID-19, including optimal dosing for COVID-19 outcomes, is also warranted for immediate investigation.

Three Doses of Vitamin D and Cognitive Outcomes in Older Women: A Double-Blind Randomized Controlled Trial.

Vitamin D may affect cognitive performance, but previous studies are either short term or observational. We conducted a randomized controlled trial of vitamin D supplementation on domain-specific cognitive measures in postmenopausal women. Overweight/obese women with serum 25-hydroxyvitamin D (25OHD) levels less than 30 ng/mL were recruited. Vitamin D3 supplementation (600, 2,000, or 4,000 IU/d) was randomly assigned in a double-blinded manner for 1 year. Serum 25-hydroxyvitamin D, osteocalcin (total and undercarboxylated), amyloid beta, parathyroid hormone, and estradiol were analyzed before and after supplementation. Cognitive tests were administered after treatment. The women (58 ± 6 years; body mass index, 30.0 ± 3.5 kg/m2) had a baseline serum 25-hydroxyvitamin D level of 22.6 ± 5.8 ng/mL that increased to 30.2 ± 5.6, 36.0 ± 4.9, and 40.8 ± 7.0 ng/mL in the 600, 2,000, and 4,000 IU/d groups, respectively (p < .001). Participants taking 2,000 IU/d compared to other doses performed better in learning and memory tests (p < .05), yet the 4,000 IU/d group had a slower reaction time compared to the 600 IU/d group. Multiple regression indicated that serum undercarboxylated osteocalcin predicted tasks associated with reaction time and executive function, whereas body mass index and parathyroid hormone negatively predicted reaction time and executive function (p ≤ .01). These data suggest that vitamin D has differential effects on domain-specific cognitive measures and that a higher dose may negatively affect reaction time.

Validation of a Newly Developed Food Frequency Questionnaire to Assess Dietary Intakes of Magnesium.

Magnesium (Mg) intake is an important indication of an individual's Mg status, but no validated food frequency questionnaire (FFQ) to assess intake currently exists. The purpose of this study was to develop and investigate the validity of a semi-quantitative Mg food frequency questionnaire (MgFFQ) against a 14-day food diary to assess average daily Mg intakes. In this cross-sectional study, 135 adults aged 18 to 75 completed the 33-item MgFFQ and a 14-day food diary to assess their Mg intakes. Coefficients of variance, Pearson's correlation coefficients, and/or Spearman's rank correlation coefficient tests were used to determine the relationship between the MgFFQ and the average Mg intake from the 14-day food diary among all participants, men, women, age groups, and body mass index (BMI) groups. The correlation between the MgFFQ and the 14-day food diary was significant (p < 0.05) for all participants (r = 0.798), men (r = 0.855), women (r = 0.759), normal weight (r = 0.762), overweight (r = 0.858), and obese (r = 0.675) weight statuses, and in all age groups. The calcium to magnesium intake (Ca:Mg) ratio in all participants was higher than optimal, 3.39 (2.11). Our results suggest that the MgFFQ is a valid method to capture Mg intake over an extended period of time, therefore acting as a valuable tool to quickly determine Mg intake.

Low dietary magnesium intake alters vitamin D-parathyroid hormone relationship in adults who are overweight or obese.

Vitamin D metabolism is dependent on magnesium (Mg) as a cofactor; therefore, poor Mg status may alter the relationship between vitamin D metabolite serum 25-hydroxyvitamin D (s25OHD) and serum parathyroid hormone (sPTH). We hypothesized that low dietary Mg intake may alter sPTH response to s25OHD in a population with excess body weight, thereby leading to a worsening of cardiometabolic health. To explore this hypothesis, we conducted a cross-sectional study on adults who were either overweight or obese (owt/ob). Dietary Mg intake was measured using a Mg food frequency questionnaire (MgFFQ). Body composition information was measured using Dual Energy X-ray Absorptiometry (DXA). Blood samples were obtained for all biochemical analyses. A total of 57 participants, 22 to 65 years of age, with a body mass index between 25 to 45 kg/m2 were divided into 3 groups, according to dietary Mg intake percentiles (Low Mg Group = <33 percentile, Medium Mg Group = 33 to 66 percentile, High Mg Group = >66 percentile). Higher s25OHD was negatively associated with lower sPTH in the High Mg Intake group (r = -0.472, P = .041), but not in other groups. A positive relationship between s25OHD and serum high-molecular weight adiponectin concentrations was observed in the High Mg Group (r = 0.532, r = 0.022), but not in other groups. Serum Interleukin-6 concentrations were negatively associated with s25OHD (r = -0.316, P = .017) for the entire study group. Based on these results, our study demonstrated that a low dietary Mg intake may alter PTH response to 25OHD.

Sedentary behavior time as a predictor of hemoglobin A1c among adults, 40 to 59 years of age, living in the United States: National Health and Nutrition Examination Survey 2003 to 2004 and 2013 to 2014.

BACKGROUND: Sedentary behavior activities have been associated with an increased risk of type 2 diabetes. Aim: Our aim was to determine whether sedentary behavior time (SBT) is predictive of hemoglobin A1c (HbA1c) ≥ 6.5% (48 mmol/mol). METHODS: We used cross-sectional data, adults 40 to 59 years of age, from the National Health and Nutrition Examination Survey (NHANES) for 2003 to 2004 and 2013 to 2014. Responses to questions on the Physical Activity Questionnaire regarding time watching television/videos, and time spent sitting in front of a computer per day were compiled into tertiles. Binary logistic regression analysis was used to determine whether SBT was a predictor of a HbA1c ≥ 6.5% adjusting for age, sex, race and ethnicity, and body mass index. RESULTS: In a univariate model, adults reporting ≥ 8 hours of SBT in NHANES 2003-2004 had 2.02 increased odds of a HbA1c ≥ 6.5% (OR = 2.02, 95% CI: 1.31, 3.13, p < 0.0001) compared to adults reporting ≤ 3 hours. After adjusting the regression model for age, sex, race and ethnicity, and body mass index, adults reporting ≥ 8 hours of SBT in NHANES 2003 to 2004 had 1.72 increased odds of HbA1c ≥ 6.5% (OR = 2.02, 95% CI: 1.10, 2.68, p < 0.0001) compared to adults reporting ≤ 3 hours of SBT. Reported SBT was not a predictor of HbA1c ≥ 6.5% for NHANES 2013 to 2014. CONCLUSION: Reported SBT was a predictor of HbA1c ≥ 6.5% among adults, 40 to 59 years of age, in NHANES 2003 to 2004, but was not a predictor in 2013 to 2014.

The Endocrine Role of Bone in Cardiometabolic Health.

PURPOSE OF REVIEW: The purpose of this review is to discuss the current knowledge about major bone regulating hormones vitamin D, parathyroid hormone (PTH), estrogen and bone metabolism markers osteocalcin (OC), bone-specific alkaline phosphatase (BAP), N-terminal propeptide of type 1 collagen (P1NP), and c-terminal type 1 collagen (CTX) and their mechanistic effects on cardiometabolic health. RECENT FINDINGS: Bone regulating hormones, nutrients, and turnover markers influence different aspects of cardiometabolic health including body composition, cardiovascular function, and glycemic control. While most observational research supports a relationship between bone as an endocrine organ and cardiometabolic outcomes, there are limited human clinical trials to strengthen a causal link between the two. While the associations between bone and cardiometabolic health are beginning to be understood based on findings from large observations studies, further exploration of bone's causal influence on health outcomes in humans and the underlying mechanisms of effect are necessary.

Can bone-regulating hormones and nutrients help characterize the metabolically healthy obese phenotype.

BACKGROUND:: Bone-regulating hormones and nutrients play an important role in influencing metabolic health. AIM:: The aim of this study was to determine whether bone-regulating hormones and nutrients, such as parathyroid hormone (PTH), 25-hydroxyvitamin D (25OHD), and magnesium (Mg) could be used to characterize the metabolically healthy obese (MHO) phenotype. METHODS:: This study included 27 overweight or obese participants (14 men/13 women) classified as MHO ( n = 14) or metabolically unhealthy obese (MUO) ( n = 13) based on the presence or absence of metabolic abnormalities, determined by percentage body fat, percentage trunk fat, and waist circumference. Biochemical (serum concentrations of hormones and cytokines such as PTH, 25OHD, ionized Mg (iMg), cytokines, lipids, glycemic indices), physiological (percentage body fat, percentage trunk fat, blood pressure (BP)), and dietary intake (Mg intake, calcium intake) measurements were obtained. RESULTS:: Serum PTH concentrations were significantly lower ( p = 0.005) in the MHO group (39.68 ± 11.06 pg/mL) compared with the MUO group (63.78 ± 25.82 pg/mL). Serum iMg concentrations were higher ( p = 0.052) in the MHO group (0.565 ± 0.41 mmol/L) than in the MUO group (0.528 ± 0.050 mmol/L). Serum concentrations of osteocalcin were also higher (10.37 ± 3.70 ng/mL) in the MHO compared with the MUO (6.51 ± 4.14 ng/mL) group ( p = 0.017). The MHO group had significantly lower serum insulin concentrations ( p = 0.006) and diastolic BP ( p = 0.035). Concentrations of serum 25OHD, total triglycerides, C-reactive protein and systolic BP did not differ between groups. CONCLUSIONS:: These findings suggest that bone-regulating hormones and nutrients, especially serum PTH, osteocalcin concentrations, and dietary Mg intakes, can help to characterize the MHO phenotype.

Serum Parathyroid Hormone Responses to Vitamin D Supplementation in Overweight/Obese Adults: A Systematic Review and Meta-Analysis of Randomized Clinical Trials.

Obesity is often associated with vitamin D deficiency and secondary hyperparathyroidism. Vitamin D supplementation typically leads to the reductions in serum parathyroid hormone (PTH) levels, as shown in normal weight individuals. Meanwhile, the dose of vitamin D supplementation for the suppression of PTH may differ in overweight and obese adults. We conducted a systematic review and meta-analysis of randomized controlled trials to determine the dose of vitamin D supplementation required to suppress PTH levels in overweight/obese individuals. We identified 18 studies that examined overweight or obese healthy adults who were supplemented with varying doses of vitamin D3. The primary outcomes examined were changes in PTH and serum 25-hydroxyvitamin D (25OHD) levels from baseline to post-treatment. The results of the meta-analysis showed that there was a significant treatment effect of vitamin D supplementation on PTH, total standardized mean difference (SMD) (random effects) = -0.38 (95% CI = -0.56 to -0.20), t = -4.08, p < 0.001. A significant treatment effect of vitamin D supplementation was also found on 25OHD, total SMD (random effects) = 2.27 (95% CI = 1.48 to 3.06) t = 5.62, p < 0.001. Data from available clinical trials that supplemented adults with D3 ranging from 400 IU to 5714 IU, showed that 1000 IU of vitamin D supplementation best suppressed serum PTH levels, total SMD = -0.58, while vitamin D supplementation with 4000 IU showed the greatest increase in serum 25OH levels. Vitamin D and calcium supplementation of 700 IU and 500 mg, respectively, also showed a significant treatment effect on the suppression of PTH with a total SMD = -5.30 (95% CI = -9.72 to -0.88). In conclusion, the meta analysis of available clinical trials indicates that 1000 IU vitamin D supplementation can suppress serum PTH levels, while 4000 IU of vitamin D was associated with the largest increase in serum 25OHD levels in the overweight and obese population.

Obesity Prevention in Older Adults.

The number of older adults living in the USA, 65 years of age and older, has been steadily increasing. Data from the National Health and Nutrition Examination Survey (NHANES), 2007-2010, indicate that more than one-third of older adults, 65 years of age and older, were obese. With the increased rate of obesity in older adults, the purpose of this paper is to present research on different methods to prevent or manage obesity in older adults, namely dietary interventions, physical activity interventions, and a combination of dietary and physical activity interventions. In addition, research on community assistance programs in the prevention of obesity with aging will be discussed. Finally, data on federal programs for older adults will also be presented.

Moderate weight loss in obese and overweight men preserves bone quality.

BACKGROUND: Weight loss (WL) negatively affects bone mineral density (BMD) in older populations and has specifically been shown in women. OBJECTIVE: In this prospective controlled trial, we examined variables of bone quality and endocrine changes after intentional WL in men. DESIGN: Thirty-eight overweight and obese [mean ± SD body mass index (in kg/m²): 31.9 ± 4.4; age: 58 ± 6 y] men were recruited to either WL through caloric restriction or weight maintenance (WM) for 6 mo. RESULTS: There was a -7.9 ± 4.4% and +0.2 ± 1.6% change in body weight in the WL and WM groups, respectively. There was a greater increase in femoral neck and total body BMD and bone mineral content (BMC) in the WM group than in the WL group (P-interaction effect < 0.05). In contrast, there was a trend for the tibia cortical thickness and area to decrease more in the WM group than in the WL group (P ≤ 0.08). There was a decrease in the periosteal circumference in both groups over time (P < 0.01) and no statistically significant changes in trabecular bone. Circulating total, free, and bioavailable estradiol decreased in the WL group compared with the WM group, and changes were different between groups (P < 0.05). Serum total and bioavailable testosterone increased in both groups (P < 0.01). Serum 25-hydroxyvitamin D increased to a similar extent in both groups (P < 0.05). CONCLUSIONS: Moderate WL in overweight and obese men did not decrease BMD at any anatomical site or alter cortical and trabecular bone and geometry. Also, despite increased BMD at some sites when maintaining excess body weight, cortical bone showed a trend in the opposite direction.

Does bone loss begin after weight loss ends? Results 2 years after weight loss or regain in postmenopausal women.

OBJECTIVE: Short-term weight loss is accompanied by bone loss in postmenopausal women. The longer-term impact of weight loss on bone in reduced overweight/obese women compared with women who regained their weight was examined in this study using a case-control design. METHODS: Postmenopausal women (N = 42; mean [SD] body mass index, 28.3 [2.8] kg/m; mean [SD] age, 60.7 [5.5] y) were recruited 2 years after the start of a 6-month weight loss trial; those who maintained their weight (weight loss maintainer [WL-M] group) were matched to a cohort of women who regained their weight (weight loss regainer [WL-R] group). Serum hormones and bone markers were measured in a subset. Bone mineral density (BMD) at the femoral neck, trochanter, spine, radius, and total body, and soft-tissue composition were taken at baseline, 0.5 years, and 2 years. RESULTS: During weight loss, both groups lost 9.3% (3.4%) of body weight, with no significant difference between the groups. After weight loss, weight change was -0.1% (2.7%) and 6.0% (3.3%) in the WL-M (n = 22) and WL-R (n = 20) groups, respectively. After 2 years, both groups lost BMD at the femoral neck and trochanter (P ≤ 0.01), whereas only the WL-M group reduced BMD at the 1/3 radius (P < 0.001). There was greater BMD loss at the trochanter (-6.8% [5.7%]) and 1/3 radius (-4.5% [3.3%]) in the WL-M group compared with the WL-R group after 2 years. Multiple linear regression showed that change in leg fat mass (but not trunk fat) contributed to trochanter BMD loss (P < 0.05). CONCLUSIONS: After 2 years, there is no BMD recovery of weight reduction-induced bone loss, irrespective of weight regain. These data suggest that the period after weight loss may be an important point in time to prevent bone loss for those who maintain weight and those who regain weight.

The effect of obesity on the relationship between serum parathyroid hormone and 25-hydroxyvitamin D in women.

CONTEXT: Obesity is associated with lower serum concentrations of 25-hydroxyvitamin D (25OHD) and higher intact PTH. The threshold of 25OHD needed to maximally suppress intact PTH has been suggested as a marker of optimal vitamin D status. OBJECTIVE: In this study, we hypothesized that whereas the obese have a higher serum PTH and lower 25OHD, suppression of serum PTH by 25OHD would be independent of body weight. DESIGN, SETTING, AND PARTICIPANTS: We performed a retrospective analysis on 383 women (ages 24-75 y) with a wide range of body weights (43-185 kg) who were stabilized to 1-1.2 g calcium/d for 1 month before blood draw. Body composition, serum PTH, 25OHD, calcium, and creatinine were measured. Locally weighted regression and smoothing scatterplots were used to depict the association between serum PTH and 25OHD. A nonlinear exponential model determined the point for near maximal suppression of PTH by 25OHD. RESULTS: The point for near maximal suppression of PTH by 25OHD for all women (body mass index, 31.4 ± 7.7 kg/m²) occurred at a 25OHD concentration of 21.7 ng/mL (95% confidence interval, 28-48 ng/mL). No point of maximal suppression was found for nonobese women, yet in the obese women (n = 207; body mass index, >30 kg/m²) suppression of PTH occurred at a 25OHD concentration of 11.1 ng/mL (95% confidence interval, 4.7-17.5 ng/mL). CONCLUSIONS: These results suggest that if PTH is suppressed at a lower serum 25OHD in the obese compared to the entire population, the lower average 25OHD concentrations in the obese may not have the same physiological significance as in the general population.

Vitamin D supplementation and calcium absorption during caloric restriction: a randomized double-blind trial.

BACKGROUND: Weight loss (WL) is associated with a decrease in calcium absorption and may be one mechanism that induces bone loss with weight reduction. OBJECTIVE: Because vitamin D supplementation has been shown to increase true fractional calcium absorption (TFCA), the goal of this study was to examine the effect of vitamin D during WL or weight maintenance (WM). DESIGN: A randomized, placebo-controlled, double-blind 6-wk study was conducted in 82 postmenopausal women [BMI (in kg/m(2); ±SD): 30.2 ± 3.7] with 25-hydroxyvitamin D [25(OH)D] concentrations <70 nmol/L during either WL or WM. All women were given 10 µg vitamin D(3)/d and 1.2 g Ca/d and either weekly vitamin D(3) (375 µg) or a placebo equivalent to 63 µg (2500 IU)/d and 10 µg (400 IU)/d, respectively. We measured TFCA with the use of dual-stable isotopes, 25(OH)D, parathyroid hormone, estradiol, calcitriol, and urinary calcium at baseline and 6 wk in weight loss and vitamin D(3)-supplementation (WL-D; n = 19), weight maintenance and vitamin D(3)-supplementation (WM-D; n = 20), weight loss and placebo (n = 22), and weight maintenance and placebo (n = 21) groups. RESULTS: WL groups lost 3.8 ± 1.1% of weight with no difference between vitamin D(3) supplementation and the placebo. The rise in serum 25(OH)D was greatest in the WL-D group (19.8 ± 14.5 nmol/L) compared with in WM-D (9.1 ± 10.3 nmol/L) and placebo groups (1.5 ± 10.9 nmol/L). TFCA increased with vitamin D(3) supplementation compared with placebo treatment (P < 0.01) and decreased during WL compared with WM. Serum 25(OH)D or 1,25-dihyroxyvitamin D did not correlate with TFCA. CONCLUSION: These data show that vitamin D supplementation increases TFCA and that WL decreases TFCA and suggest that, when calcium intake is 1.2 g/d, either 10 or 63 µg vitamin D/d is sufficient to maintain the calcium balance. This trial was registered at clinicaltrials.gov as NCT00473031.