Strength, but not muscle mass, is associated with mortality in the health, aging and body composition study cohort

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-alpha 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.     

Cognitive function, gait speed decline, and comorbidities: the health, aging and body composition study

BACKGROUND: Emerging evidence indicates an association between cognitive function and physical performance in late life. This study examines the relationship between cognitive function and subsequent gait speed decline among high-functioning older adults. METHODS: Measures of global cognitive function (Modified Mini Mental State Examination [3MS]) and executive control function (ECF) (a clock drawing task [CLOX 1] and the 15-item Executive Interview [EXIT 15]) were obtained in the Health, Aging, and Body Composition Study in 1999-2000. Gait-speed (meters/second) was assessed over 20 meters at usual pace. Using a mixed model, we assessed the relationship between baseline cognitive function and gait-speed change over 3 years. RESULTS: Two thousand, three hundred forty-nine older adults (mean age 75.6 +/- 2.9 years) completed the assessments. After adjustment for baseline gait speed, a 1-standard-deviation (SD) lower performance on each cognitive test was associated with greater gait-speed decline over 3 years: 0.016 m/s for the 3MS (SD = 8.1), 0.009 m/s for CLOX 1 (SD = 2.4), and 0.012 m/s for EXIT 15 (SD = 4.1) (p <.0005 for all). After adjustment for comorbidities, the effect size was attenuated for 3MS and CLOX 1, and the association for EXIT 15 was no longer significant. Depression score was most strongly associated with the EXIT 15 effect reduction. CONCLUSION: Global and executive cognitive functions predict declines in gait speed. The association of ECF with gait speed decline is attenuated by comorbid conditions, particularly depression. Elucidation of the mechanisms underlying these associations may point to new pathways for the treatment of physical decline associated with diminished cognitive function.     

Chronic kidney disease and functional limitation in older people: health, aging and body composition study

OBJECTIVES: To assess whether chronic kidney disease (CKD) is independently associated with incident physical-function limitation. DESIGN: Prospective cohort study. SETTING: Two sites: Pittsburgh, Pennsylvania, and Memphis, Tennessee. PARTICIPANTS: Two thousand one hundred thirty-five men and women aged 70 to 79 without functional limitation at baseline from the Health, Aging and Body Composition Study. MEASUREMENTS: Functional limitation was defined as difficulty in walking one-quarter of a mile or climbing 10 steps on two consecutive reports 6 months apart (in the same function). Kidney function was measured using serum cystatin C. Estimated glomerular filtration rate (eGFR), using the Modification of Diet in Renal Disease formula (<60 versus > or =60 mL/min per 1.73 m(2)), was a secondary predictor. Muscle strength, lean body mass according to dual energy x-ray absorptiometry, comorbidity, medication use, and inflammatory markers were evaluated as covariates. RESULTS: Persons in the highest (> or =1.13 mg/L) quartile of cystatin C experienced a significantly higher risk of developing functional limitation than those in the lowest (<0.86 mg/L) quartile (hazard ratio (HR)=1.70, 95% confidence interval (CI)=1.40-2.07). The association between the fourth cystatin C quartile and functional limitation remained after adjustment for demographics, lean body mass, comorbidity, muscle strength, and gait speed (HR=1.41, 95% CI=1.13-1.75), although the association was attenuated after adjustment for markers of inflammation (HR=1.15, 95% CI=0.90-1.46). Similar results were found for eGFR less than 60 mL/min per 1.73 m(2), although the association with functional limitation remained after adjustment for inflammatory markers (HR=1.30, 95% CI=1.08-1.56). CONCLUSION: CKD is associated with the development of functional impairment independent of comorbidity, body composition, and tests of strength and physical performance. The mechanism may be related to a heightened inflammatory state in CKD.     

Impact of age on postoperative events and mortality in cardiac surgery

BACKGROUND AND OBJECTIVE: The number of "older" patients undergoing cardiac surgery is steadily increasing. In the year 2000, 37% of all patients who underwent a cardiac operation in Germany were > or = 70 years. Looking at data from our institution, we analyzed the impact of age on postoperative events and mortality in cardiac surgery. PATIENTS AND METHODS: Data from 7,048 patients who underwent cardiac surgery in our institution from January 1996 until January 2002 were analyzed. For all patients, EuroSCORE and the corresponding age-stripped value were calculated. All recorded postoperative complications and 30-day mortality were statistically analyzed. RESULTS: EuroSCORE as well as the age-stripped EuroSCORE showed a significant rise with increasing age in the total number of patients as well as in the patients, who did not die during the first 30 days after the operation. 30-day mortality and the incidence of postoperative complications increased significantly with age. While the EuroSCORE showed a significant age-dependent increase in patients who died within 30 days after the operation, the age-stripped EuroSCORE did not reveal a significant discrepancy in mortality with respect to age. CONCLUSION: Our data confirm that the age alone of a patient undergoing cardiac surgery has to be regarded as one of the important independent risk factors for mortality. In order to limit mortality in the steadily growing number of older and multimorbid patients undergoing cardiac surgery, exceptional emphasis has to be put on patient selection and therapeutic measures to improve preoperative status.     

Diabetes mellitus, glycemic control, and incident depressive symptoms among 70- to 79-year-old persons: the health, aging, and body composition study

BACKGROUND: Cross-sectional studies find an elevated prevalence of depression among subjects with diabetes mellitus (DM). The causal mechanisms and temporal sequence of this association have not been clearly delineated. This study investigated the prospective relationship between DM and depressive symptoms. METHODS: The Health, Aging, and Body Composition Study was a cohort study conducted in the metropolitan areas of Memphis, Tenn, and Pittsburgh, Pa. The analysis included 2522 community-dwelling subjects, aged 70 to 79 years, without baseline depressive symptoms. Incident depressed mood was defined as use of antidepressants at follow-up visits or presence of depressive symptoms (score >or=10 on the 10-item Center for Epidemiological Studies Depression scale). Presence of incident depressed mood at 2 consecutive annual clinic visits defined the incidence of recurrent depressed mood. Diabetes mellitus status, glycosylated hemoglobin (HbA1c) level, and DM-related comorbidities were assessed at baseline. Diabetes mellitus status was further characterized as absent, controlled (HbA1c level <7%), or uncontrolled (HbA1c level >or=7%). Discrete time survival analysis was used to estimate depressive events risk. RESULTS: During a mean follow-up of 5.9 years, participants with DM had a higher age-, sex-, race-, and site-adjusted incidence of depressed mood (23.5% vs 19.0%) (P = .02) and recurrent depressed mood (8.8% vs 4.3%) (P<.001) than those without DM. Diabetes mellitus was associated with a 30% increased risk of incident depressed mood (odds ratio [OR], 1.31; 95% confidence interval [CI], 1.07-1.61), which was attenuated after adjustment for DM-related comorbidities (OR, 1.20; CI, 0.97-1.48). A stronger relationship was observed between DM and recurrent depressed mood (OR, 1.91; CI, 1.32-2.76), particularly among participants with poor glycemic control. CONCLUSION: Among well-functioning older adults, DM is associated with increased risk of depressive symptoms.     

The association of race and socioeconomic status with cardiovascular disease indicators among older adults in the health,aging, and body composition study

OBJECTIVES: We hypothesized that older Black adults would have a higher prevalence of cardiovascular disease (CVD) than White adults, as indicated by elevated systolic blood pressure (SBP), low ankle-arm blood pressure index (AAI), and left ventricular hypertrophy (LVH). But, accounting for a broad interpretation of socioeconomic status (SES) (i.e., education, family income, home ownership, and other assets) would reduce these differences. METHODS: Data are from the Health, Aging, and Body Composition study, a longitudinal clinical research study of 3,075 well-functioning adults aged 70-79, in which 46% of women and 33% of men are Black. Logistic regression modeled racial and SES differences in CVD indicators. RESULTS: Being Black was significantly associated with elevated SBP (men only), low AAI, and LVH, and remained significant after accounting for each SES measure. The racial association with CVD was reduced the most by income for elevated SBP in men, other assets for low AAI in women and men, and other assets for LVH in men. DISCUSSION: Contrary to the age-as-leveler theory, being Black was strongly associated with CVD indicators, and accounting for SES did not reduce this association. Whether other SES measures, such as access to care, could explain the racial association remains to be explored.     

Cross-sectional associations between trunk muscle composition, back pain, and physical function in the health, aging and body composition study

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.     

Effects of depression and social integration on the relationship between alcohol consumption and all-cause mortality

Aims This study was designed to assess the potentially confounding influences of social integration and depression on the form of the relationship between alcohol consumption and all‐cause mortality. Design, participants and measurement Respondents from the 1984 US National Alcohol Survey (N = 5177) were followed by searching the National Death Index (NDI) through 1995; 540 were identified as deceased. Predictor variables in a Cox proportional hazards model included gender, ethnicity, marital status, income, smoking, age and alcohol consumption (volume and patterns). Two social variables and their interactions with alcohol consumption were added, the Center for Epidemiological Studies Depression (CES‐D) scale and an eight‐item social isolation scale. Findings The J‐shaped risk curve for all‐cause mortality by volume was approximated for men but not significantly for women. In addition heavy drinking occasions independently contributed to mortality in men. Low social integration (bottom 12%) had no significant effects on mortality or on the relationship between alcohol consumption and mortality curve. Inclusion of the interaction between alcohol consumption and depression proved significant for heavy male drinkers (> six drinks on average per day) and for female former drinkers with heavy drinking occasions. In both cases, the respective subgroup, which additionally was depressed, had about four times the risk of a life‐time abstainer. Conclusions The relationship of alcohol consumption to 11‐year all‐cause mortality in a general population indicated little confounding effect of social isolation, but revealed important interactions with depression for heavy male drinkers and heavy female ex‐drinkers.     

Prospective study of alcohol consumption in the United States: quantity, frequency, and cause-specific mortality

Background: Alcohol average volume (quantity multiplied by frequency) has been associated with mortality in drinkers. However, average volume may mask associations due to quantity or frequency alone. Methods: We prospectively assessed relationships between alcohol quantity and frequency, and mortality from all‐causes, cardiovascular disease, cancer, and other‐causes in a cohort created by linking the 1988 National Health Interview Survey (response rate 87%) to the National Death Index through 2002. Participants were 20,765 current drinkers age ≥ 18 years. At 14‐year follow‐up 2,547 had died. Results: For quantity, among men who consumed ≥5 drinks (compared to 1 drink) on drinking days, adjusted relative risks (RR) of mortality were: for cardiovascular disease, 1.30 [95% confidence interval (CI) 0.96–1.75; p for linear trend (p‐trend) = 0.0295], for cancer, 1.53 (95% CI 1.11–2.09; p‐trend = 0.0026), and for other‐causes, 1.42 (95% CI 1.08–1.87; p‐trend = 0.0029); among women for other‐causes, 2.88 (95% CI 1.61–5.12; p‐trend = 0.0010). For frequency, among men in the highest frequency quartile (compared to the lowest), RR were: for cardiovascular disease, 0.79 (95% CI 0.63–0.99; p‐trend = 0.0330), for cancer, 1.23 (95% CI 0.95–1.59; p‐trend = 0.0461), and for other‐causes, 1.30 (95% CI 1.01–1.67; p‐trend = 0.0070); among women, for cancer, 1.65 (95% CI 1.12–2.45, p‐trend = 0.0031). Average volume obscured effects of quantity alone and frequency alone, particularly for cardiovascular disease in men where quantity and frequency trended in opposite directions. Conclusions: Alcohol quantity and frequency were independently associated with cause‐specific mortality. Accumulating evidence of their differential effects may, in the future, be useful for clinical and public health recommendations.     

The loss of skeletal muscle strength, mass, and quality in older adults: the health, aging and body composition study

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 ( approximately 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.     

Hearing sensitivity in older adults: associations with cardiovascular risk factors in the health, aging and body composition study

OBJECTIVES: To examine the association between cardiovascular disease (CVD) and its risk factors and age‐associated hearing loss in a cohort of older black and white adults. DESIGN: Cross‐sectional cohort study. SETTING: The Health, Aging, and Body Composition (Health ABC) Study, a community‐based cohort study of older adults from Pittsburgh, Pennsylvania, and Memphis, Tennessee. PARTICIPANTS: Two thousand forty‐nine well‐functioning adults (mean age 77.5; 37% black). MEASUREMENTS: Pure‐tone audiometry measurement and history of clinical CVD were obtained at the fourth annual follow‐up visit. Pure‐tone averages in decibels reflecting low (250, 500, and 1,000 Hz), middle (500, 1,000, and 2,000 Hz), and high (2,000, 4,000, and 8,000 Hz) frequencies were calculated for each ear. CVD risk factors, aortic pulse‐wave velocity (PWV), and ankle–arm index (AAI) were obtained at study baseline. RESULTS: In sex‐stratified models, after adjustment for age, race, study site, and occupational noise exposure, risk factors associated with poorer hearing sensitivity in men included high triglyceride levels, high resting heart rate, and history of smoking. In women, poor hearing sensitivity was associated with high body mass index, high resting heart rate, fast PWV, and low AAI. CONCLUSION: Modifiable risk factors for CVD may play a role in the development of age‐related hearing loss.     

The association between physical function and lifestyle activity and exercise in the health, aging and body composition study

Objectives: To determine whether older adults who exercise demonstrate higher levels of physical function than those who do not exercise but are physically active throughout the day. Design: Cross‐sectional examination of baseline data from the Health, Aging and Body Composition (Health ABC) study. Setting: Health ABC field centers in Pittsburgh, Pennsylvania, and Memphis, Tennessee. Participants: Three thousand seventy‐five well‐functioning black and white men and women aged 70 to 79. Measurements: Physical activity and exercise were assessed using a modified leisure‐time physical activity questionnaire. Participants were classified as inactive (reporting <1,000 kcal/wk of exercise activity and ≤2,719 kcal/wk of total physical activity), lifestyle active (reporting <1,000 kcal/wk of exercise activity and >2,719 kcal/wk of total physical activity), or exerciser (reporting≥1,000 kcal/wk of exercise activity). Physical function measures included the Established Populations for the Epidemiologic Studies of the Elderly (EPESE) battery, the Health ABC battery, a 400‐m walk test, and isokinetic strength testing of the knee extensors. Results: The lifestyle active and exerciser groups had similar total activity levels (men: 6,135 kcal/wk and 6,734 kcal/wk, respectively; P=.108; women: 5,695 kcal/wk and 5,854 kcal/wk, respectively; P=.335). When examining lower extremity performance in relation to physical activity, a progressive trend was evident, with the inactive individuals most likely to have impaired performance on the EPESE battery (men: 33.7%, 24.3%, and 19.1%, P<.001; women: 49.9%, 37.3%, and 28.4%, P<.001; inactive, lifestyle active, and exerciser, respectively). Progressive trends of similar magnitude were present for the Health ABC battery, time to walk 400 m, and knee extensor strength. In multivariate linear regression, those in the inactive and lifestyle active groups had poorer scores on the Health ABC performance battery than individuals in the exercise group after controlling for demographic factors and prevalent disease (men: inactive β=?0.27, P<.001, lifestyle active β=?0.07, P=.032; women: inactive β=?0.23, P<.001, lifestyle active β=?0.07, P<.059). After controlling for demographic factors and prevalent disease, the lifestyle active and exercisers had similar proportions of functionally limited older persons (scoring <10 on the EPESE battery). Conclusion: Older adults who participate in 20 to 30 minutes of moderate‐intensity exercise on most days of the week have better physical function than older persons who are active throughout the day or who are inactive. Any type of physical activity is better than no activity for protection against functional limitations, but exercise confers greater benefit for physical capacity.     

The effect of total body water on the relationship between alcohol consumption and carbohydrate-deficient transferrin

BACKGROUND: Clinicians agree that alcoholism commonly is overlooked in their patients, and that treating the symptoms without directing therapy to the underlying cause at best delays an inevitable decline in the patient's general health and well-being. The current analysis focused on carbohydrate-deficient transferrin (CDT), a promising biological marker of dangerous alcohol consumption. METHODS: Included in our study were men (730) and women (613) from study sites in Canada, Brazil, and Japan. All subjects were participants in the WHO/ISBRA Study on State and Trait Markers of Alcoholism, who completed an extensive demographic, medical, and behavioral survey and provided blood samples for determination of CDT levels. ANOVA and chi2 test for equality were used to examine the effect of total body water (TBW) on the alcohol consumption/CDT relationship. To examine whether accounting for differences in TBW improved the diagnostic properties of CDT when used as a state marker for alcohol consumption, odds ratios were calculated for men and women separately. RESULTS: Our results show that accounting for individual differences in TBW significantly influenced the alcohol consumption/CDT dose-response relationship. The effect of TBW was different for men compared with women. When we used a consumption cutoff value of 40 g/day and the CDTect recommended cutoffs (20 for men; 27 for women), adjusting for differences in TBW significantly increased diagnostic performance of CDT in men but not women. CONCLUSIONS: The dependence of CDT measures on body water content needs to be taken into account to maximize the performance of CDT as an effective state marker of alcohol consumption in males.     

Anxiety symptoms and decline in physical function over 5 years in the health, aging and body composition study

OBJECTIVES: To examine the relationship between anxiety and functional decline. DESIGN: A 5-year longitudinal cohort study of well-functioning adults. SETTING: The Health, Aging and Body Composition (Health ABC) Study. PARTICIPANTS: Two thousand nine hundred forty adults aged 70 to 79 (48% male, 41% black), initially free of self-reported mobility difficulty. MEASUREMENTS: In 1997/98, presence of three anxiety symptoms (feeling fearful, tense or keyed up, or shaky or nervous) from the Hopkins Symptom Checklist were ascertained. Physical function was examined over 5 years using the Health ABC performance battery (continuous range 0-4) consisting of chair stands, usual and narrow course gait speed, and difficulty with standing balance and self-reported mobility, defined as difficulty walking one-quarter of a mile or difficulty climbing 10 steps. RESULTS: Participants with anxiety symptoms had similar baseline physical performance scores. After adjustment for potential confounders, subjects with anxiety symptoms had similar declines in physical performance over 5 years as participants without anxiety symptoms. Adults with anxiety symptoms were more likely to report incident mobility difficulty, with a hazard ratio of 1.4 (95% confidence interval=1.3-1.6), compared with adults without anxiety symptoms. These results persisted after adjustment for depressive symptoms, demographics, comorbidity, and use of antianxiety, depressant, and sedative hypnotic medications. CONCLUSION: Anxiety symptoms are not associated with declines in objectively measured physical performance over 5 years but are associated with declines in self-reported functioning. Future studies are needed to determine why anxiety has a differential effect on performance-based and self-reported measures of functioning.     

Impact of systemic inflammation on the relationship between insulin resistance and all-cause and cancer-related mortality

BackgroundInsulin resistance and inflammation play an important role in a variety of chronic diseases.ObjectiveWe investigated the influence of systemic inflammation on the relationship between insulin resistance and mortality risk in apparently healthy adults.MethodsThis study examined the mortality outcomes for 165,849 Koreans enrolled in a health-screening program. The subjects were divided into four groups according to their homeostatic model assessment of insulin resistance (HOMA-IR) and high-sensitivity C-reactive protein (hs-CRP) levels: group 0, HOMA-IR < 75% and hs-CRP < 2.0 mg/L; group 1, HOMA-IR ≥ 75% and hs-CRP < 2.0 mg/L; group 2, HOMA-IR < 75% and hs-CRP ≥ 2.0 mg/L; and group 3, HOMA-IR ≥ 75% and hs-CRP ≥ 2.0 mg/L. The Cox proportional hazard models were used to assess hazard ratios (HRs) and 95% confidence intervals (CIs) for all-cause, cardiovascular disease, and cancer-related mortality.ResultsDuring the follow-up period of 1,417,325.6 person-years, a total of 1316 deaths (182 from cardiovascular disease) occurred. The multivariate-adjusted HRs for all-cause mortality were significantly higher in groups 2 (HR 1.40; 95% CI: 1.19–1.64) and group 3 (HR 1.68; 95% CI: 1.34–2.10) than that in group 0. For cardiovascular mortality, the sex-adjusted hazards were also significantly higher in groups 2 and 3 than that in group 0; however, this increased risk disappeared during multivariate analysis. Groups 2 and 3 had significantly higher risk for cancer-related mortality than group 0, with multivariate-adjusted hazard ratios of 1.48 (95% CI: 1.18–1.86) and 1.84 (95% CI: 1.35–2.51), respectively.ConclusionsSystemic inflammation can be used to stratify the subjects according to the all-cause and cancer-related mortality risks, irrespective of the insulin-resistance status. And this tendency is most pronounced in cancer-related mortality.     

Trunk muscle composition as a predictor of reduced functional capacity in the health, aging and body composition study: the moderating role of back pain

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 x 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.     

Association between thyroid dysfunction and total cholesterol level in an older biracial population: the health, aging and body composition study

BACKGROUND: Thyroid dysfunction increases with age. Less is known about the prevalence of thyroid disease in older black adults and whether an association between thyroid function and serum cholesterol level exists, as in older white adults. METHODS: A cross-sectional study of 2799 well functioning white and black participants, aged 70 to 79 years, were recruited for a population-based study. Participants underwent thyrotropin, free thyroxine, and total cholesterol testing; a medical history; and physical measurements. RESULTS: Among the entire cohort, 94% were euthyroid based on biochemical testing results. Approximately 10% were taking thyroid hormones. Subclinical hypothyroidism was the most prevalent disorder (3.1% of all participants not taking thyroid hormones), but black men and women had lower rates of this condition than white men and women. After excluding those taking thyroid or lipid medication and adjusting for potential confounders, an elevated thyrotropin level (>5.5 mIU/mL) was associated with a 9 mg/dL (0.23 mmol/L) higher cholesterol level, and a suppressed thyrotropin level (<0.35 mIU/mL) was associated with a 19 mg/dL (0.49 mmol/L) lower cholesterol level. CONCLUSION: Healthy community-dwelling older black adults have a lower prevalence of thyroid dysfunction compared with older white adults, but the association between increased thyrotropin and increased cholesterol levels is similar in both races.