We investigated whether low subcutaneous thigh fat is an independent risk factor for unfavourable glucose and lipid levels, and whether these associations differ between sexes, and between white and ...black adults. Our secondary aim was to investigate which body composition characteristics (lean tissue, fat tissue) are reflected by anthropometric measures (waist and thigh circumference).
Anthropometric measurements and computed tomography of the abdomen and of the thigh were performed for all participants of the Health, Aging and Body Composition Study, who were aged 70-79 years. Fasting glucose, triglycerides and HDL-cholesterol, and 2-h postload glucose were determined.
After excluding those already diagnosed with diabetes or dyslipidaemia, we analysed data from 2,106 participants. After adjustment for abdominal subcutaneous and visceral fat, and intermuscular thigh fat, larger thigh subcutaneous fat area was statistically significantly associated with lower ln-transformed triglycerides standardised beta (95% CI) -0.12 (-0.20 to -0.04) in men and -0.13 (-0.21 to -0.05) in women and higher ln-HDL-cholesterol 0.10 (0.02 to 0.19) and 0.09 (0.01 to 0.18), respectively. The associations with lower glucose levels were strong in men -0.11 (-0.20 to -0.02) for fasting and -0.14 (-0.23 to -0.05) for postload glucose, but not statistically significant in women -0.02 (-0.10 to 0.07) and -0.04 (-0.13 to 0.05), respectively. There were no differences in the associations between white and black persons. Waist circumference was more strongly associated with abdominal subcutaneous fat, and this association became stronger with increasing BMI, whereas the association with visceral fat became weaker. Thigh circumference was equally dependent on thigh fat and thigh muscle in men, whereas in women the fat component was the main contributor.
Larger subcutaneous thigh fat is independently associated with more favourable glucose (in men) and lipid levels (in both sexes) after accounting for abdominal fat depots, which are associated with unfavourable glucose and lipid levels. Anthropometric measures reflect different fat depots at different levels of BMI at the abdomen, and reflect both fat and lean tissue at the thigh. These results emphasise the importance of accurate measures of regional body composition when investigating potential health risks.
Several studies have linked dietary patterns to insulin sensitivity and systemic inflammation, which affect risk of multiple chronic diseases. The purpose of this study was to investigate the dietary ...patterns of a cohort of older adults, and to examine relationships of dietary patterns with markers of insulin sensitivity and systemic inflammation.
The Health, Aging and Body Composition (Health ABC) Study is a prospective cohort study of 3075 older adults. In Health ABC, multiple indicators of glucose metabolism and systemic inflammation were assessed. Food intake was estimated with a modified Block food frequency questionnaire. In this study, dietary patterns of 1751 participants with complete data were derived by cluster analysis.
Six clusters were identified, including a 'healthy foods' cluster, characterized by higher intake of low-fat dairy products, fruit, whole grains, poultry, fish and vegetables. In the main analysis, the 'healthy foods' cluster had significantly lower fasting insulin and homeostasis model assessment of insulin resistance values than the 'breakfast cereal' and 'high-fat dairy products' clusters, and lower fasting glucose than the 'high-fat dairy products' cluster (P≤0.05). No differences were found in 2-h glucose. With respect to inflammation, the 'healthy foods' cluster had lower interleukin-6 than the 'sweets and desserts' and 'high-fat dairy products' clusters, and no differences were seen in C-reactive protein or tumor necrosis factor-α.
A dietary pattern high in low-fat dairy products, fruit, whole grains, poultry, fish and vegetables may be associated with greater insulin sensitivity and lower systemic inflammation in older adults.
Abstract Background and aims Although dietary fats and cholesterol have previously been associated with risk of cardiovascular disease (CVD) in middle-aged populations, less is known among older ...adults. The purpose of this study was to determine the association between dietary fats, cholesterol, and eggs and CVD risk among community-dwelling adults aged 70–79 in the Health, Aging and Body Composition Study. Methods and results Diet was assessed using an interviewer-administered 108-item food frequency questionnaire ( n = 1941). CVD events were defined as a confirmed myocardial infarction, coronary death, or stroke. Relative rates of CVD over 9 years of follow-up were estimated using Cox proportional hazards models. During follow-up, there were 203 incident cases of CVD. There were no significant associations between dietary fats and CVD risk. Dietary cholesterol (HR (95% CI): 1.47 (0.93, 2.32) for the upper vs. lower tertile; P for trend, 0.10) and egg consumption (HR (95% CI): 1.68 (1.12, 2.51) for 3+/week vs. <1/week; P for trend, 0.01) were associated with increased CVD risk. However, in sub-group analyses, dietary cholesterol and egg consumption were associated with increased CVD risk only among older adults with type 2 diabetes (HR (95% CI): 3.66 (1.09, 12.29) and 5.02 (1.63, 15.52), respectively, for the upper vs. lower tertile/group). Conclusions Dietary cholesterol and egg consumption were associated with increased CVD risk among older, community-dwelling adults with type 2 diabetes. Further research on the biological mechanism(s) for the increased CVD risk with higher dietary cholesterol and frequent egg consumption among older adults with diabetes is warranted.
Background
Prenatal folic acid supplementation is recommended to prevent birth defects. Some foods are fortified in the USA to ensure sufficient intake among reproductive‐aged women. However, high ...prenatal folate exposure may be a risk factor for childhood atopic diseases. We investigated associations between prenatal folate and early childhood wheeze and atopic dermatitis in a US cohort.
Methods
We studied 858 mother‐child dyads, enrolled prenatally. Folate was measured in 2nd and 3rd trimester maternal plasma. Parents reported current wheeze (previous 12 months) and healthcare provider diagnosis of atopic dermatitis at 3 years. We examined associations using logistic regression, modeling folate continuously and dichotomously (< or ≥20 ng/mL), a level often considered supraphysiologic.
Results
Over half of women were African American and on Medicaid. Median (interquartile range) folate levels were 22.6 (15.9‐30.0) and 23.1 (16.1‐30.0) ng/mL for 2nd and 3rd trimesters, respectively. Current wheeze and atopic dermatitis were reported for 20.4% and 26.8% of children, respectively. Second trimester folate as a continuous exposure was not significantly associated with outcomes. Decreased odds of current wheeze were observed in children born to mothers who had 2nd trimester folate ≥20 ng/mL (adjusted odds ratios = 0.67, 95% confidence interval = 0.46, 0.97) compared to children with maternal levels <20 ng/mL. Third trimester folate was not associated with outcomes.
Conclusions
High plasma folate in mid‐pregnancy was associated with decreased odds of current wheeze at age 3. Our findings do not support harmful effects of high prenatal folate levels on childhood atopic diseases in this setting.
Background. The loss of muscle mass is considered to be a major determinant of strength loss in aging. However, large-scale longitudinal studies examining the association between the loss of mass and ...strength in older adults are lacking. Methods. Three-year changes in muscle mass and strength were determined in 1880 older adults in the Health, Aging and Body Composition Study. Knee extensor strength was measured by isokinetic dynamometry. Whole body and appendicular lean and fat mass were assessed by dual-energy x-ray absorptiometry and computed tomography. Results. Both men and women lost strength, with men losing almost twice as much strength as women. Blacks lost about 28% more strength than did whites. Annualized rates of leg strength decline (3.4% in white men, 4.1% in black men, 2.6% in white women, and 3.0% in black women) were about three times greater than the rates of loss of leg lean mass (∼1% per year). The loss of lean mass, as well as higher baseline strength, lower baseline leg lean mass, and older age, was independently associated with strength decline in both men and women. However, gain of lean mass was not accompanied by strength maintenance or gain (ß coefficients; men, −0.48 ± 4.61, p =.92, women, −1.68 ± 3.57, p =.64). Conclusions. Although the loss of muscle mass is associated with the decline in strength in older adults, this strength decline is much more rapid than the concomitant loss of muscle mass, suggesting a decline in muscle quality. Moreover, maintaining or gaining muscle mass does not prevent aging-associated declines in muscle strength.
The dietary inflammatory index (DII) measured at one time point is associated with risk of several chronic diseases, but disease risk may change with longitudinal changes in DII scores. Data are ...lacking regarding changes in DII scores over time; therefore, we assessed changes in the DII in the Women's Health Initiative (WHI).
DII scores were calculated using data from repeated food frequency questionnaires in the WHI Observational Study (OS; n=76 671) at baseline and year 3, and the WHI Dietary Modification trial (DM; n=48482) at three time points. Lower DII scores represent more anti-inflammatory diets. We used generalized estimating equations to compare mean changes in DII over time, adjusting for multiple comparisons, and multivariable-adjusted linear regression analyses to determine predictors of DII change.
In the OS, mean DII decreased modestly from -1.14 at baseline to -1.50 at year 3. In the DM, DII was -1.32 in year 1, -1.60 in year 3 and -1.48 in year 6 in the intervention arm and was -0.65 in year 1, -0.94 in year 3 and -0.96 in year 6 in the control arm. These changes were modified by body mass index, education and race/ethnicity. A prediction model explained 22% of the variance in the change in DII scores in the OS.
In this prospective investigation of postmenopausal women, reported dietary inflammatory potential decreased modestly over time. Largest reductions were observed in normal-weight, highly educated women. Future research is warranted to examine whether reductions in DII are associated with decreased chronic disease risk.
Background. Although muscle strength and mass are highly correlated, the relationship between direct measures of low muscle mass (sarcopenia) and strength in association with mortality has not been ...examined. Methods. Total mortality rates were examined in the Health, Aging and Body Composition (Health ABC) Study in 2292 participants (aged 70–79 years, 51.6% women, and 38.8% black). Knee extension strength was measured with isokinetic dynamometry, grip strength with isometric dynamometry. Thigh muscle area was measured by computed tomography (CT) scan, and leg and arm lean soft tissue mass were determined by dual energy x-ray absorptiometry (DXA). Both strength and muscle size were assessed as in gender-specific Cox proportional hazards models, with age, race, comorbidities, smoking status, level of physical activity, fat area by CT or fat mass by DXA, height, and markers of inflammation, including interleukin-6, C-reactive protein, and tumor necrosis factor-α considered as potential confounders. Results. There were 286 deaths over an average of 4.9 (standard deviation = 0.9) years of follow-up. Both quadriceps and grip strength were strongly related to mortality. For quadriceps strength (per standard deviation of 38 Nm), the crude hazard ratio for men was 1.51 (95% confidence interval, 1.28–1.79) and 1.65 (95% confidence interval, 1.19–2.30) for women. Muscle size, determined by either CT area or DXA regional lean mass, was not strongly related to mortality. In the models of quadriceps strength and mortality, adjustment for muscle area or regional lean mass only slightly attenuated the associations. Further adjustment for other factors also had minimal effect on the association of quadriceps strength with mortality. Associations of grip strength with mortality were similar. Conclusion. Low muscle mass did not explain the strong association of strength with mortality, demonstrating that muscle strength as a marker of muscle quality is more important than quantity in estimating mortality risk. Grip strength provided risk estimates similar to those of quadriceps strength.
An excessive amount of adipose tissue may contribute to sarcopenia and may be one mechanism underlying accelerated loss of muscle mass and strength with aging. We therefore examined the association ...of baseline total body fat with changes in leg lean mass, muscle strength, and muscle quality over 7 years of follow-up and whether this link was explained by adipocytokines and insulin resistance.
Data were from 2,307 men and women, aged 70-79 years, participating in the Health, Aging, and Body Composition study. Total fat mass was acquired from dual energy X-ray absorptiometry. Leg lean mass was assessed by dual energy X-ray absorptiometry in Years 1, 2, 3, 4, 5, 6, and 8. Knee extension strength was measured by isokinetic dynamometer in Years 1, 2, 4, 6, and 8. Muscle quality was calculated as muscle strength divided by leg lean mass.
Every SD greater fat mass was related to 1.3 kg more leg lean mass at baseline in men and 1.5 kg in women (p < .01). Greater fat mass was also associated with a greater decline in leg lean mass in both men and women (0.02 kg/year, p < .01), which was not explained by higher levels of adipocytokines and insulin resistance. Larger fat mass was related to significantly greater muscle strength but significantly lower muscle quality at baseline (p < .01). No significant differences in decline of muscle strength and quality were found.
High fatness was associated with lower muscle quality, and it predicts accelerated loss of lean mass. Prevention of greater fatness in old age may decrease the loss of lean mass and maintain muscle quality and thereby reducing disability and mobility impairments.
Background. Associations between trunk muscle composition and physical function have not been examined previously in older adults. We hypothesized that lower trunk muscle area and attenuation (higher ...fat infiltration) are associated with decreased functional capacity. Methods. The study sample consisted of a biracial cohort of well functioning men (739) and women (788) aged 70–79 from the Pittsburgh site of the Health, Aging and Body Composition (Health ABC) study. Computed tomography was used to measure trunk muscle area (cm2) and muscle attenuation (Hounsfield Unit HU) of the following muscle groups: lumbar paraspinals, lateral abdominals, and rectus abdominis. An average score was calculated for both trunk area and attenuation. The Health ABC Physical Performance Battery (PPB) and its individual components (usual and narrow walk, chair stands, and standing balance) were used to measure functional capacity. Results. Linear regression analyses adjusting for demographic factors, height, body fat, thigh muscle composition, disease status, and low back pain (LBP) found that average trunk muscle area was not associated with any element of functional capacity (p >.10), whereas average trunk muscle attenuation was positively associated with the Health ABC Physical Performance Battery (p <.05) and chair stands (p <.001). Participants reporting higher LBP severity during the past year had lower muscle attenuation (p <.001 for trend), but there was no difference in average trunk muscle area according to LBP status. Conclusions. Findings suggest a link between trunk muscle composition and history of LBP as well as reduced functional capacity in older adults. Improving trunk muscle quality may lead to reduced LBP severity and improved functional status.
Background. Cross-sectionally, lower trunk muscle attenuation (higher fat infiltration) has been associated with poorer physical function in older adults. We hypothesize that lower trunk muscle ...attenuation will be associated with lower functional capacity 3 years later and that back pain status will moderate this relationship. Methods. The study sample consisted of a biracial cohort of well functioning men (739) and women (788) aged 70–79 years from the Pittsburgh site of the Health, Aging and Body Composition (Health ABC) study. Computed tomography was used to measure trunk muscle area and attenuation of the lumbar paraspinal, lateral abdominal, and rectus abdominus muscles at baseline. The Health ABC Physical Performance Battery (usual and narrow walk, chair stands, and standing balance) was used to measure functional capacity at the first and fourth annual clinic visits. Results. Regardless of back pain status, average trunk muscle attenuation (but not muscle area) was positively associated with overall physical performance, particularly balance (p <.01), in a fully adjusted model. The association between trunk attenuation and functional capacity was significantly stronger in participants with at least moderate back pain in the year prior to baseline (p <.05 for interaction; attenuation × back pain). Participants with moderate to extreme back pain had a greater decline in function over time (p <.05). Conclusions. Older adults with poorer trunk muscle composition (higher fat infiltration) exhibit reduced functional capacity, especially balance, 3 years later. Improving trunk muscle composition may be an important yet overlooked approach to maintain function and potentially reduce balance impairments, particularly in persons with a history of back pain.
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