OBJECTIVEOlder 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 METHODSWe 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.RESULTSPrevalence 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 (β: −0.115 ± 0.024 m/s, P < 0.001) and 400-m (β:−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.CONCLUSIONSIn older persons, diabetes is associated with reduced muscle strength and worse muscle quality. These impairments are important contributors of walking limitations related to diabetes.

Sarcopenia identified by the European Working Group on Sarcopenia in Older People criteria is a relatively common condition in Italian octogenarians, and its prevalence increases with aging. Correlates of sarcopenia identified in this study might suggest new approaches for prevention and treatment of sarcopenia.

BackgroundNew evidence is emerging on the importance of lean body mass during periods of illness and recovery. The preservation of lean body mass during such periods of intense stress impacts both patient and treatment outcomes. However, data concerning the incidence of sarcopenia among older people during hospitalization are scarce. The objective of this study was to evaluate the development of sarcopenia in a sample of hospitalized older subjects.MethodsWe used data of 394 participants from the multicentre Italian Study conducted by the Gruppo Lavoro Italiano Sarcopenia—Trattamento e Nutrizione (GLISTEN) in 12 Acute Care Wards (Internal Medicine and Geriatrics) of University Hospitals across Italy. This study was designed to determine the prevalence of sarcopenia at hospital admission and the change in muscle mass and strength during hospitalization. Sarcopenia was defined as low skeletal mass index (kg/m2) along with either low handgrip strength or slow walking speed [European Working Groups on Sarcopenia in Older People (EWGSOP) criteria]. Estimation of skeletal muscle mass was performed by bioelectrical impedance analysis (BIA).ResultsThe mean age of the 394 enrolled patients (including 211 females who accounted for 53% of the sample) was 79.6 ± 6.4 years. Among those without sarcopenia at hospital admission, 14.7% of the study sample met the EWGSOP sarcopenia diagnostic criteria at discharge. The incidence of sarcopenia during hospitalization was significantly associated with the number of days spent in bed but was not correlated with the total length of hospital stay. In particular, patients who developed sarcopenia spent an average of 5.1 days in bed compared with 3.2 days for those with no sarcopenia at discharge (P = 0.02). Patients with sarcopenia showed a significantly lower body mass index compared with non‐sarcopenic peers (25.0 ± 3.8 kg/m2 vs. 27.6 ± 4.9 kg/m2, respectively; P < 0.001). Similarly, the skeletal mass index at admission was significantly lower among patients who developed sarcopenia during hospital stay.ConclusionsIncident sarcopenia during hospital stay is relatively common and is associated with nutritional status and the number of days of bed rest.

Type 2 diabetes, a common metabolic disease in older people, is a major risk factor for functional limitation, impaired mobility, and loss of independence. In older people, the pathogenesis of functional limitation and disability is complex and multifactorial. A number of potential pathways are involved including cardiovascular disease, peripheral neuropathy, overweight, osteoarthritis, visual deficit, and cognitive impairment, conditions that are all more prevalent among patients with diabetes. Sarcopenia, a geriatric condition characterized by a progressive and generalized loss of skeletal muscle mass and strength, is also involved in the pathogenesis of functional limitations and disability. Recent research has shown that older patients with type 2 diabetes are often affected by skeletal muscle impairment, leading to reduced muscle strength and physical function. Insulin resistance, hyperglycemia, muscle fat infiltration, and peripheral neuropathies are hypothesized as the fundamental biological mechanisms leading to muscle impairment in people with diabetes. This review summarizes the current literature on the biological pathways responsible for skeletal muscle dysfunction in type 2 diabetes and analyzes the role of decline in muscle strength and quality on the association between diabetes and mobility disability.

Background: Prevalence of sarcopenia is substantial in most geriatrics settings, but estimates vary greatly across studies because of difference in population characteristics, diagnostic criteria, and methods used to assess muscle mass, muscle strength, and physical performance. We investigated the feasibility of the European Working Group on Sarcopenia in Older People (EWGSOP) algorithm assessment in hospitalized older adults and analyzed prevalence and clinical correlates of sarcopenia. Methods: Cross-sectional analysis of 655 participants enrolled in a multicenter observational study of older adults admitted to 12 acute hospital wards in Italy. Sarcopenia was assessed as low skeletal mass index (kg/m 2 ) plus either low handgrip strength or low walking speed (EWGSOP criteria). Skeletal muscle mass was estimated using bioimpedance analysis. Results: Of the 655 patients (age 81.0 ± 6.8 years; women 51.9%) enrolled in the study, 275 (40.2%) were not able to perform the 4-m walking test because of medical problems. The overall prevalence of sarcopenia on hospital admission was 34.7% (95% confidence interval 28-37) and it steeply increased with aging (p < .001). In multivariable analysis, patients with sarcopenia on hospital admission were older and were more likely to be male and to have congestive heart failure, cerebrovascular disease, and severe basic activities of daily living disability. The prevalence of sarcopenia was inversely correlated with body mass index.