BackgroundBoth low dietary protein intake and inadequate distribution of protein over the three mealtimes have been reported in older Caucasian adults, but the association between protein intake at each meal and muscle mass has not been studied. The purpose of this study was to evaluate dietary protein intake and distribution by mealtimes, and to explore their association with appendicular skeletal muscle mass in apparently healthy older adults.MethodsThis was a cross-sectional pilot study that included 78 people over the age of 60 years. Caloric and protein intake were estimated on the basis of three nonconsecutive 24-hour diet recalls and appendicular skeletal muscle mass by dual-energy X-ray absorptiometry.ResultsMen consumed 13.4 g of protein/day more than women (P < 0.05). The estimated value of dietary protein intake was 0.9 g/kg/day. In this sample, 28% of subjects did not cover 100% of the dietary reference intake for protein. Lower consumption of dietary protein was found at breakfast and dinnertime compared with the recommended amount of 25–30 g (P < 0.05). Also, the study observed that appendicular skeletal muscle mass in men and women who consumed <25 g of protein at each mealtime was different from that found in the group that consumed >25 g of protein at one, two, or three mealtimes.ConclusionWhile protein intake was higher than current recommendations, it failed to achieve the values reported as necessary to prevent sarcopenia. In addition, there was under-consumption of protein per mealtime, especially at breakfast and dinner.

Background: In recent studies, the usefulness of the phase angle (PA) to assess geriatric conditions such as sarcopenia and frailty has been evaluated. However, there are no useful cut-off points for clinical research and/or practice.Objective: To analyze PA cut-off points associated with sarcopenia and frailty in adults of 50-64 years old and older adults in Mexico City.Design: Cross-sectional analysis of the FraDySMex cohort study (Frailty, Dynapenia, and Sarcopenia in Mexican Adults).Setting and Participants: 498 people were included, 78.7% women, aged 71.1 ± 9.5 years. Methods: The sarcopenia measurements were made according to the European Working Group on Sarcopenia in Older People (EWGSOP) (2019) (by dynamometer to evaluate hand grip strength and dual energy X-ray absorptiometry (DXA) for appendicular muscle mass), and the frailty through the physical frailty phenotype with cut-off points adjusted to the Mexican population. The PA was evaluated by bioelectrical impedance analysis (BIA), tetrapolar to 50 Hz, other variables such as socio-demographic, comorbidity, cognitive status, and functional dependence were evaluated.Results: The prevalence of frailty was 10.6% and sarcopenia 10.0%. The mean of the PA was 4.6° ± 0.70°. The PA cut-off point for frailty in adults 50 to 64 years was ≤4.3° [sensitivity (S) = 91.95%, specificity (Sp) 66.77%, AUROC (Area Under the Receiver Operating Characteristic) curve = 0.9273 95% CI (0.8720-0.9825)]; the PA cut-off point for sarcopenia was ≤4.3 [S = 91.95%, Sp = 66.77%, AUROC = 0.9306 95% CI (0.8508-1.000)]. The PA cut-off for frailty in adults ≥ 65 years was ≤4.1° [S = 72.37%, Sp 71.43%, AUROC = 0.7925 95%, CI (0.7280-0.8568)] for sarcopenia was ≤4.1° [S = 72.76%, Sp 73.81%, AUROC = 0.7930 95% CI (0.7272-0.8587)]. These cut-off points showed a significant association between PA with frailty (OR 4.84; 95% CI 2.61-8.99) and sarcopenia (OR 8.44; 95% CI 3.85-18.4) after adjusted by age, sex, BMI, comorbidity index and cognitive impairment.Conclusions and Implications: These cut-off points of PA could be useful for the screening of sarcopenia and frailty in Mexican adults of 50 years and older in centers that have BIA.

Background and Objectives. Skeletal muscle and skeletal muscle indices in young adults from developing countries are sparse. Indices and the corresponding cut-off points can be a reference for diagnoses of sarcopenia. This study assessed skeletal muscle using dual-energy X-ray absorptiometry (DXA) in healthy male and female subjects aged 20–40 years and compared their appendicular skeletal muscle mass (ASM) and total-body skeletal muscle (TBSM) indices using certain cut-off points published in the literature. Methods. A sample of 216 healthy adults men and women from northwest Mexico was included. Body composition was assessed by DXA and several published DXA-derived skeletal muscle indices were compared. Results. Both, ASM and TBSM were higher in men compared to the women group (23.0 ± 3.4 versus 15.9 ± 1.6 kg; P < 0.05 and 26.5 ± 4.1 versus 16.9 ± 1.9 kg; P < 0.05, resp.). These differences were also valid for both indices. When derived cut-off points were compared with the most reported indices, significant differences were found. Interpretation and Conclusion. Published cut-off points from Caucasians are higher than cut-off point derived in this sample of Mexican subjects. The new DXA-derived cut-off points for ASM proposed herein may improve diagnoses of sarcopenia in the geriatric Mexican population.

Background. Variation in the prevalence of sarcopenia is related to the skeletal muscle index cutoff points applied. The objective of this pilot study was to examine the recruitment process for testing different sarcopenia definitions (ASMI cutoffs) in older Mexican adults. It explored whether the prevalence of sarcopenia decreased by applying ethnic- and gender-specific, DXA-derived appendicular skeletal muscle index (ASMI)-cutoff points in the definitions, as well as some associated factors in a sample of community-dwelling older Mexican people. Methods. This is a pilot feasibility study that included a convenience sample of 217 community-dwelling older adults. Volunteers underwent DXA measurements and an assessment of functional status based on hand grip strength and physical performance. Six definitions were formed based on the 2010 EWGSOP criteria, but using different cutoff points for each of the three components, including regional cutoff points for ASMI derived from young Mexican adults. Several risk factors for sarcopenia were also assessed. Results. The prevalence of sarcopenia varied according to the different definitions applied. The lowest level was found with the definition that applied regional ASMI-cutoff points (p<0.01). The sarcopenic older adults had significant lower body weight, fat mass, and fat-free mass (FFM) than the nonsarcopenic subjects. The risk of sarcopenia increased with age and low FFM (p<0.001). Conclusion. The present study demonstrates the feasibility of the main study, and our data support the notion that using regional ASMI cutoff points resulted in a low prevalence of sarcopenia. Therefore, it is preferable to estimate the prevalence of this condition using ethnic- and gender-specific cutoff points and to explore associated factors such as low FFM.