Role of muscle mass and muscle quality in the association between diabetes and gait speed.

OBJECTIVE: Older people with type 2 diabetes are at high risk of mobility disability. We investigated the association of diabetes with lower-limb muscle mass and muscle quality to verify whether diabetes-related muscle impairments mediate the association between diabetes and low walking speed. RESEARCH DESIGN AND METHODS: We performed a cross-sectional analysis of 835 participants (65 years old and older) enrolled in the InCHIANTI (Invecchiare in Chianti, aging in the Chianti area) population-based study. Total, muscular, and fat cross-sectional areas of the calf and relative muscle density were measured using peripheral quantitative computerized tomography. Indicators of muscle performance included knee-extension torque, ankle plantar flexion and dorsiflexion strength, lower-extremity muscle power, and ankle muscle quality (ratio of ankle strength to the muscle area [kilograms per centimeters squared]). Gait performance was assessed by 4- and 400-m walking speed. Diabetes was ascertained by standard American Diabetes Association criteria. RESULTS: Prevalence of diabetes was 11.4%. After adjustment for age and sex, participants with diabetes had lower muscle density, knee and ankle strength, and muscle power and worse muscle quality (all P < 0.05). Diabetic participants were also slower on both 4-m (ß: -0.115 ± 0.024 m/s, P < 0.001) and 400-m (ß:-0.053 ± 0.023 m/s, P < 0.05) walking tests. In multivariable linear regression models, lower-limb muscle characteristics accounted for 24.3 and 15.1% of walking speed difference comparing diabetic and nondiabetic subjects in the 4- and 400-m walks, respectively. CONCLUSIONS: In older persons, diabetes is associated with reduced muscle strength and worse muscle quality. These impairments are important contributors of walking limitations related to diabetes.

The relationship between plasma carotenoids and depressive symptoms in older persons.

OBJECTIVE: We examined the cross-sectional and longitudinal relationship between plasma carotenoids and depressive symptoms over a 6-year follow-up in older persons. METHODS: This research is part of the InCHIANTI Study, a prospective population-based study of older persons in Tuscany, Italy. The sample for this analysis included 958 women and men aged 65 years and older. Plasma total carotenoids were assessed at baseline. Depressive symptoms were assessed at baseline and at the 3- and 6-year follow-up using the Center for Epidemiological Studies-Depression Scale (CES-D). Depressed mood was defined as CES-D ≥ 20. RESULTS: At baseline, higher total carotenoids level were associated with lower probability of depressed mood (OR = 0.82, 95%CI = 0.68-0.99, P = 0.04) after adjustment for sociodemographic, health and inflammation. After the exclusion of participants with baseline depressed mood and use of antidepressants, higher total carotenoids level were associated with lower risk of incident depressed mood (OR = 0.72, 95%CI = 0.52-0.99, P = 0.04) at 6-year follow-up, after adjustment for confounders plus baseline CES-D. Inflammatory marker Interleukin-1 receptor antagonist partially mediated this association. CONCLUSIONS: Low plasma concentrations of carotenoids are associated with depressive symptoms and predict the development of new depressive symptoms in older persons. Understanding the mechanism of this association may reveal potential targets for prevention and treatment.

Mediterranean diet and mobility decline in older persons.

We examined whether adherence to a Mediterranean-style diet has positive effects on mobility assessed over a 9-year follow-up in a representative sample of older adults. This research is part of the InCHIANTI Study, a prospective population-based study of older persons in Tuscany, Italy. The sample for this analysis included 935 women and men aged 65 years and older. Adherence to the Mediterranean diet was assessed at baseline by the standard 10-unit Mediterranean diet score (MDS). Lower extremity function was measured at baseline, and at the 3-, 6- and 9-year follow-up visits using the short physical performance battery (SPPB). At baseline, higher adherence to Mediterranean diet was associated with better lower body performance. Participants with higher adherence experienced less decline in SPPB score, which was of 0.9 points higher (p<.0001) at the 3-year-follow, 1.1 points higher (p=0.0004) at the 6-year follow-up and 0.9 points higher (p=0.04) at the 9-year follow-up compared to those with lower adherence. Among participants free of mobility disability at baseline, those with higher adherence had a lower risk (HR=0.71, 95% CI=0.51-0.98, p=0.04) of developing new mobility disability. High adherence to a Mediterranean-style diet is associated with a slower decline of mobility over time in community-dwelling older persons. If replicated, this observation is highly relevant in terms of public health.

Trail Making Test predicts physical impairment and mortality in older persons.

OBJECTIVES: To examine whether performance in the Trail Making Test (TMT) predicts mobility impairment and mortality in older persons. DESIGN: Prospective cohort study. SETTING: Community-dwelling older persons enrolled in the Invecchiare in Chianti (InCHIANTI) Study. PARTICIPANTS: Five hundred eighty-three participants aged 65 and older and free of major cognitive impairment (Mini-Mental State Examination score >21) with baseline data on TMT performance. Of these, 427 performed the Short Physical Performance Battery (SPPB) for the assessment of lower extremity function at baseline and after 6 years. Of the initial 583 participants, 106 died during a 9-year follow-up. MEASUREMENTS: The TMT Parts A and B (TMT-A and TMT-B) and SPPB were administered at baseline and 6-year follow-up. Impaired mobility was defined as an SPPB score less than 10. Vital status was ascertained over a 9-year follow-up. RESULTS: InCHIANTI participants in the fourth quartile of the time to complete TMT-B minus time to complete TMT-A (TMT (B-A)) were significantly more likely to develop an SPPB score less than 10 during the 6-year follow-up than those in the first quartile (relative risk (RR)=2.4, 95% confidence interval (CI)=1.4-3.9, P=.001). After adjusting for potential confounders, these findings were substantially unchanged (RR=2.2, 95% CI=1.4-3.6, P=.001). Worse performance on the TMT was associated with significantly greater decline in SPPB score over the 6-year follow-up, after adjusting for age, sex, and baseline SPPB scores (beta=-0.01, standard error=0.003, P=.004). During the 9-year follow-up, 18.2% of the participants died. After adjustment for age and sex, the proportion of participants who died was higher in participants in the worst than the best performance quartile of TMT (B-A) scores (hazard ratio (HR)=1.7, 95% CI=1.0-2.9, P=.048). Results were similar in a parsimonious adjusted model (HR=1.8, 95% CI=1.0-3.2, P=.04). CONCLUSION: Performance on the TMT is a strong, independent predictor of mobility impairment, accelerated decline in lower extremity function, and death in older adults living in the community. The TMT could be a useful addition to geriatric assessment.

Carotenoids as protection against disability in older persons.

The purpose was to examine the relationship of total plasma carotenoids, an indicator of fruit and vegetable intake, with walking speed and severe walking disability in older adults. Nine hundred twenty-eight men and women aged 65 to 102 years from the Invecchiare in Chianti (Aging in the Chianti Area [InCHIANTI]) study, a population-based cohort in Tuscany, Italy, were studied. Plasma carotenoids were measured at enrollment (1998-2000), and walking speed over 4 meters and 400 meters distance were assessed at enrollment and 6 years later (2004-2006). At enrollment, 85 of 928 (9.2%) participants had severe walking disability (defined as being unable to walk or having a walking speed at the 4-meter walking test < 0.4 m/sec). After adjusting for potential confounders, participants with high total plasma carotenoids were significantly less likely to have prevalent severe walking disability (odds ration [OR] 0.59, 95% confidence interval [CI] 0.38-0.90, p = 0.01) and had higher walking speed over 4 meters (beta = 0.024, standard error [SE] = 0.011, p = 0.03) and over 400 meters (beta = 0.019, SE = 0.010, p = 0.04). Of 621 participants without severe walking disability at enrollment who were seen 6 years later, 68 (11.0%) developed severe walking disability. After adjusting for potential confounders, higher total plasma carotenoids were associated with a significantly lower risk of developing severe walking disability (OR 0.51, 95% CI 0.30-0.86, p = 0.01) and were associated with a less steep decline in 4-meter walking speed over a 6-year follow-up (n = 579; beta = 0.026, SE = 0.012, p = 0.03) and with lower incidence rates of being unable to successfully complete the 400-meter walking test at the 6-year follow-up visit (beta = -0.054, SE = 0.03, p = 0.04). High plasma carotenoids concentrations may be protective against the decline in walking speed and the development of severe walking disability in older adults.

Classification of residents in nursing homes in Tuscany (Italy) using Resource Utilization Groups Version III (RUG-III).

BACKGROUND AND AIMS: Samples of nursing homes in Tuscany (Italy) classify their residents and determine their case-mix according to the Resource Utilization Groups System, Version III (RUG-III). METHODS: A large sample of nursing homes was selected, based on willingness to participate, representation of both public and private institutions, and wide geographic representation. Two registered nurses assessed all residents using the RUG questionnaire. The information collected was then used to group residents into 44 RUGs, and facility-specific case-mix indices were calculated using the RUG-specific weights previously validated in Italy. RESULTS: A total of 3981 residents from 93 nursing homes were assessed. Most residents were over 75 years old (87.4%) and women (68.6%). A large percentage was classified into RUGs within the following primary categories: reduced physical function (33.6%), impaired cognition (17.6%) and clinically complex (17.6%). The resulting nursing home case-mix indices ranged from 0.627 to 1.108 (mean 0.807+/-0.110). No significant association was found between type of facility, level of fees, or extent of staff in the nursing homes and their case-mix indices. CONCLUSIONS: RUGIII can provide information on types of nursing home residents and their care needs. This is useful for monitoring and evaluating long-term care services for the elderly, and allows for more effective planning and allocation of staffing and financial resources.