Heliodoro Alemán-Mateo

Physiological effects beyond the significant gain in muscle mass in sarcopenic elderly men: evidence from a randomized clinical trial using a protein-rich food

Background Sarcopenia is strongly associated with an inadequate intake of dietary protein. Dietary protein supplementation boosts muscle-protein synthesis and increases muscle mass in the elderly. This study tested whether adding a protein-rich food, ricotta cheese, to the habitual diet increased total appendicular skeletal muscle mass and strength in elderly people. Methods Participants (n = 40), were sarcopenic elderly men and women over 60 years of age. Two comparison groups were formed at random and followed for 3 months: the intervention group received 210 g/day of ricotta cheese plus the habitual diet, while the control group followed the habitual diet with no additional intervention. Total appendicular skeletal muscle (TASM) was assessed by dual-energy X-ray absorptiometry, while strength was measured using a handheld dynamometer at baseline and after the intervention period. The primary outcomes were the percentage of relative change in TASM and strength. Results The percentage of relative change in TASM was not significant between the groups after the intervention period. Muscle strength improved in the intervention group, but showed only a tendency towards significance (P = 0.06). Secondary analysis showed that the men in the intervention group gained 270 g in TASM compared to those in the control group, and improved their fasting insulin levels (P = 0.05), muscle strength, lean body mass in the arms, and body weight variables. Conclusion The results of this study indicate that a nutritional intervention using a high-quality protein food, specifically ricotta cheese, in order to increase the amount of protein intake might not be regarded as fully promising in elderly men and women with sarcopenia. However, the gender effects on muscle strength, lean tissue in the arms, homeostatic assessment of insulin resistance, and body weight detected in this study suggest that additional research is needed on elderly male subjects with sarcopenia.

Insufficient amounts and inadequate distribution of dietary protein intake in apparently healthy older adults in a developing country: implications for dietary strategies to prevent sarcopenia

Background Both 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. Methods This 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. Results Men 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. Conclusion While 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.

Body composition by hydrometry (deuterium oxide dilution) and bioelectrical impedance in subjects aged >60 y from rural regions of Cuba, Chile and Mexico

BACKGROUND: In Latin American and Caribbean countries such as Chile, Mexico and Cuba, the population over 60 y has increased steadily. In this age group, there is scarce information about body composition, particularly for those living in rural areas.OBJECTIVE: The purpose of this study was to determine body composition in free-living and healthy elderly subjects >60 y from rural areas of Chile, Cuba and Mexico using deuterium oxide dilution and bioelectrical impedance (BIA) and to develop and cross-validate a predictive equation for this group of subjects by BIA for future use as a field technique.SUBJECTS: The study included 133 healthy subjects (73 males and 60 females) >60 y from rural regions of Cuba, Chile and Mexico.MEASUREMENTS: Total body water, body weight, height and other anthropometric and BIA variables (resistance and reactance) were measured.METHODS: Total body water was determined by deuterium oxide dilution, and fat-free mass (FFM)/fat mass were derived from this measurement. The total sample was used in a split-sample internal cross-validation. BIA and other anthropometric variables were integrated to multiple regression model to design the best predictive equation, which was validated in the other sample. ANOVA, multiple regression and Bland and Altmans procedure were used to analyze the data.RESULTS: Body weight, percentage of fat and fat-free mass were lower in the Cuban men and women compared with Chilean and Mexican men and women. The best predictive equation of the FFM was: FFM kg=(−7.71+(H 2/R × 0.49)+(country or ethnicity × 1.12)+(body weight × 0.27)+(sex × 3.49)+(Xc × 0.13)), where H 2 is height2 (cm); R is resistance (Ω); country: Chile=1, Mexico=2 and Cuba=3; sex: women=0 and men=1; body weight (kg) and Xc is reactance (Ω). R 2 was 0.944 and the root mean square error (RMSE) was 2.08 kg. The mean±s.d. of FFM prediction was 44.2±9.2 vs 44.6±10.1. The results of cross-validation showed no significant difference with the line of identity, showing that the predicted equation was accurate. The intercept (=–0.32) was not significantly different from zero (P=0.89) and the slope (=1.02) not significantly different from 1.0 (P>0.9). The R 2 was 0.86, RMSE=3.86 kg of FFM and the pure error was 3.83.CONCLUSION: The new BIA equation is accurate, precise and showed good agreement. The use of this equation could improve the estimates of body composition for the elderly population for these regions, as well as enhancing the opportunity to conduct studies in the elderly population from Latin America.

Association Between Insulin Resistance and Low Relative Appendicular Skeletal Muscle Mass: Evidence From a Cohort Study in Community-Dwelling Older Men and Women Participants

BACKGROUND It has been hypothesized that insulin resistance plays a role in the development of the loss of skeletal muscle; however, no cohort studies on insulin resistance and low relative appendicular skeletal muscle mass (ASM) have been published to date. Thus, we examined whether insulin resistance is associated with low relative ASM after a 4.6-year follow-up period among apparently healthy older men and women participants. METHODS This is a combined retrospective-prospective cohort study, which includes 147 community-dwelling older men and women participants. ASM was measured by dual-energy x-ray absorptiometry at baseline and follow-up. Participants with a relative change in ASM below the sex-specific 15th value were classified as the low relative ASM group. Homeostatic model assessment was used to quantify insulin resistance. Logistic regression calculated odds ratios and 95% confidence intervals for development of low relative ASM, adjusted for covariates. RESULTS The loss of ASM in the low relative ASM and normal groups was -1.8kg and -0.35kg, respectively (p ≤ .05). The low relative ASM group was older and had higher insulin and homeostatic model assessment of insulin resistance values at baseline. The risk of developing low relative ASM at 4.6-year follow-up was 2.9 times higher (95% CI, 1.00-7.8; p = .04) among the participants with homeostatic model assessment of insulin resistance levels more than 2.3. After adjusting for age, the risk increased to 3.9 times higher (95% CI, 1.3-11.5; p = .03). CONCLUSION Insulin resistance was associated with low relative ASM at 4.6-year follow-up after accounting for several covariates in a cohort of apparently healthy, well-functioning young older men and women.

Nutrient-rich dairy proteins improve appendicular skeletal muscle mass and physical performance, and attenuate the loss of muscle strength in older men and women subjects: a single-blind randomized clinical trial

Background At present, it is unknown whether the use of nutrient-rich dairy proteins improves the markers of sarcopenia syndrome. Therefore, our proposal was to investigate whether adding 210 g of ricotta cheese daily would improve skeletal muscle mass, handgrip strength, and physical performance in non-sarcopenic older subjects. Subjects and methods This was a single-blind randomized clinical trial that included two homogeneous, randomized groups of men and women over 60 years of age. Participants in the intervention group were asked to consume their habitual diet but add 210 g of ricotta cheese (IG/HD + RCH), while the control group was instructed to consume only their habitual diet (CG/HD). Basal and 12-week follow-up measurements included appendicular skeletal muscle mass (ASMM) by dual-energy X-ray absorptiometry, handgrip strength by a handheld dynamometer, and physical performance using the short physical performance battery (SPPB) and the stair-climb power test (SCPT). The main outcomes were relative changes in ASMM, strength, SPPB, and SCPT. Results ASMM increased in the IG/HD + RCH (0.6±3.5 kg), but decreased in the CG/HD (−1.0±2.6). The relative change between groups was statistically significant (P=0.009). The relative change in strength in both groups was negative, but the loss of muscle strength was more pronounced in CG/HD, though in this regard statistical analysis found only a tendency (P=0.07). The relative change in the balance-test scores was positive for the IG/HD + RCH, while in the CG/HD it was negative, as those individuals had poorer balance. In this case, the relative change between groups did reach statistical significance. Conclusion The addition of 210 g of ricotta cheese improves ASMM and balance-test scores, while attenuating the loss of muscle strength. These results suggest that adding ricotta cheese to the habitual diet is a promising dietetic strategy that may improve the markers of sarcopenia in subjects without a pronounced loss of ASMM or sarcopenia.

Four-compartment model and validation of deuterium dilution technique to estimate fat-free mass in Mexican youth

OBJECTIVE To validate the measurement of fat-free mass (FFM) with the deuterium oxide (D(2)O) dilution technique (2C) against the four-compartment (4C) model in Mexican children. METHODS This was designed as a cross-sectional, non-probabilistic study. Sixty subjects (30 male and 30 female) 6-14 y of age were recruited and completed the study during 5 mo. Total body water was measured using the D(2)O dilution technique and FFM was calculated using Fomons (6-10 y) and Lohmans (11-14 y) hydration constants. Body composition using the 4C model was calculated with Lohmans equation. RESULTS Group mean accuracy showed no differences in FFM determined by D(2)O dilution and the 4C model (1.24 kg, P > 0.4), by gender (2.1 kg, P > 0.2), or by method-by-gender interaction (P > 0.7). FFMs were 26.9 and 25.7 kg by the 4C and 2C models, respectively. The test for coincidence of slopes and intercepts between the 2C and 4C models and the line of identity were not different (P > 0.05). Precision by R(2) explained 98% of the variance (standard error of the estimate 1.2 kg). Bias for the difference in FFM was not significant (-1.27, 95% confidence interval -1.5 to -0.9) and no association between the mean of the differences and the magnitude of the measurements was found (P > 0.05). Mean bias was -1.27 kg for FFM (P > 0.05), and limits of agreement were -3.1 to 0.8 kg. CONCLUSION The D(2)O dilution technique used with these hydration constants was accurate, precise, and free of bias in Mexican children and adolescents compared with the 4C model.

Skeletal Muscle Mass Indices in Healthy Young Mexican Adults Aged 20–40 Years: Implications for Diagnoses of Sarcopenia in the Elderly Population

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.

Antropometría y composición corporal en personas mayores de 60 años. Importancia de la actividad física

Objective. To measure anthropometric indicators of body composition by electric bioimpedence, as well as physical activity, blood glucose and arterial pressure in rural people over 60 years of age. Material and methods. A total of 54 subjects over 60 years old were selected by intentional nonprobabilistic sampling. They were subjected to a standardized protocol to measure anthropometric indicators, body composition by electric bioimpedance (EBI), and physical activity was determined by an activity questionnaire. Arterial pressure and glucose tolerance levels were also measured. Analysis included Student’s t test to detect differences by sex and the association of physical activity, body composition and other variables by simple linear regression and Pearson’s correlation coefficient. Results. Physical activity correlated negatively with percent fat (r= -0.36; p= 0.007) and diastolic (r= -0.36; p= 0.006) and systolic blood pressure (r= -0.32; p= 0.018), and body mass index with post dose glucose (r= 0.31; p= 0.024). Conclusions. Physical activity in this age group may have a favorable impact with respect to the mentioned health indicators.

Hyperinsulinemia is associated with the loss of appendicular skeletal muscle mass at 4.6 year follow-up in older men and women.

BACKGROUND & AIMS Homeostasis model assessment as a marker of insulin resistance has been associated with the pronounced loss of appendicular skeletal muscle mass in older adults. In the present study, we hypothesized that hyperinsulinemia as an early predictor of insulin resistance may be associated with the loss of appendicular skeletal muscle mass (ASM). METHODS This is a cohort study that included 147 well-functioning older men and women subjects who were followed for a period of 4.6 ± 1.8 years. Lean tissue in arm and legs, or ASM, was derived from dual-energy X-ray absorptiometry at baseline with follow-up measurements to obtain the relative change. Hyperinsulinemia was defined empirically at the 75th percentile. RESULTS The relative change in ASM was negative and significant throughout the quartiles of fasting insulin levels (p ≤ 0.05); however, the loss of ASM was more pronounced in the later quartiles (-0.7 kg) compared with the relative change in Q1 and Q2 (-0.5 kg and -0.3 kg). The unadjusted analysis indicates a significant association between hyperinsulinemia and the loss of ASM (β = -0.28, 95% CI-0.57-0.009, p = 0.05), an association that remained significant after adjusting for several covariates. CONCLUSION Hyperinsulinemia as an early marker of insulin resistance was associated with the loss of ASM in a cohort study of community-dwelling older men and women subjects without other chronic health conditions. The use of fasting insulin levels >8.4 μU/mL may help clinicians identify individuals in the geriatric population who are at a high risk of loss of appendicular skeletal muscle mass.

Body Composition by Three-Compartment Model and Relative Validity of Some Methods to Assess Percentage Body Fat in Mexican Healthy Elderly Subjects

Background: In Mexico, there is scarce information about the body composition in the elderly. Some researchers have measured body fat by anthropometry and bioelectrical impedance. These techniques are practical and can be used in the field; however, proper validation is required. This implies the use of accurate and precise methods. In the elderly, Siri’s three-compartment (3C) model has been proposed as feasible alternative to the gold standard four-compartment model. Objective: To evaluate the body composition by the 3C model and the relative validity of densitometry and hydrometry methods to assess the percentage body fat (%BF) in 37 healthy Mexican elderly subjects. Methods: The body density was measured by air displacement plethysmography, total body water was evaluated by means of an isotopic dilution technique, and two different hydration factors were used to determine the fat-free mass. These measurements were used to calculate %BF by the 3C model. Accuracy and precision of the methods were tested by a two-way analysis of variance and regression procedures and bias by Bland and Altman analysis. Results: In men and women as a whole group, the %BF by the 3C model was 34.4 ± 8.01. Women had higher values of %BF as compared with men (41.7 ± 3.7 vs. 29.4 ± 6.4; p < 0.0001). The regression procedures showed that air displacement plethysmography was accurate and precise only in women and in the whole group. Regression analyses of %BF by total body water (using both hydration factors) and 3C model showed that the intercepts were not different from zero and that the slopes were not different from 1.0 in men and women separately and as group. Conclusion: In this study, the total-body water method revealed a good relative validity (accuracy, precision, and freedom from bias) as compared with the 3C model in men and women both separately and as a group and may be acceptable for the estimation of %BF in individuals or groups of healthy elderly subjects.