CT pectoralis muscle area is associated with DXA lean mass and correlates with emphysema progression in a tobacco-exposed cohort

IntroductionMuscle loss is an important extrapulmonary manifestation of COPD. Dual energy X-ray absorptiometry (DXA) is the method of choice for body composition measurement but is not widely used for muscle mass evaluation. The pectoralis muscle area (PMA) is quantifiable by CT and predicts cross-sectional COPD-related morbidity. There are no studies that compare PMA with DXA measures or that evaluate longitudinal relationships between PMA and lung disease progression.MethodsParticipants from our longitudinal tobacco-exposed cohort had baseline and 6-year chest CT (n=259) and DXA (n=164) data. Emphysema was quantified by CT density histogram parenchymal scoring using the 15th percentile technique. Fat-free mass index (FFMI) and appendicular skeletal mass index (ASMI) were calculated from DXA measurements. Linear regression model relationships were reported using standardised coefficient (β) with 95% CI.ResultsPMA was more strongly associated with DXA measures than with body mass index (BMI) in both cross-sectional (FFMI: β=0.76 (95% CI 0.65 to 0.86), p<0.001; ASMI: β=0.76 (95% CI 0.66 to 0.86), p<0.001; BMI: β=0.36 (95% CI 0.25 to 0.47), p<0.001) and longitudinal (ΔFFMI: β=0.43 (95% CI 0.28 to 0.57), p<0.001; ΔASMI: β=0.42 (95% CI 0.27 to 0.57), p<0.001; ΔBMI: β=0.34 (95% CI 0.22 to 0.46), p<0.001) models. Six-year change in PMA was associated with 6-year change in emphysema (β=0.39 (95% CI 0.23 to 0.56), p<0.001) but not with 6-year change in airflow obstruction.ConclusionsPMA is an accessible measure of muscle mass and may serve as a useful clinical surrogate for assessing skeletal muscle loss in smokers. Decreased PMA correlated with emphysema progression but not lung function decline, suggesting a difference in the pathophysiology driving emphysema, airflow obstruction and comorbidity risk.

Body Composition Measurement Improved Performance of GLIM Criteria in Diagnosing Malnutrition Compared to PG-SGA in Ambulatory Cancer Patients: A Prospective Cross-Sectional Study

Background and aims: Muscle mass reduction (MMR) is one of the three etiologic criteria in the Global Leadership Initiative on Malnutrition (GLIM) framework. This study aimed to evaluate the value of MMR in GLIM criteria among ambulatory cancer patients. Methods: A single-center prospective cross-sectional study was conducted. All participants underwent calf circumference (CC) measurement and body composition measurement by bioelectrical impedance analysis (BIA). MMR was identified by CC, fat-free mass index (FFMI), appendicular skeletal muscle index (ASMI), or combinations of the above three indicators. Patients-generated Subjective Global Assessment (PG-SGA) was used as the comparator. Results: A total of 562 cancer patients receiving intravenous treatment were evaluated. Of the participants, 62.8% (355/562) were male. The median age of the patients was 59.0 years (range, 21–82 y). The median BMI was 22.8 kg/m2 (range, 14.6–34.5 kg/m2). A total of 41.8% of patients were evaluated as malnutrition (PG-SGA ≥ 4), and 11.9% were diagnosed with severe malnutrition (PG-SGA ≥ 9). For the GLIM criteria, the prevalence of malnutrition was 26.9%, and severe malnutrition was 12.3%. For all criteria combinations of GLIM together versus PG-SGA, sensitivity was 60.4% (53.8–66.7), specificity was 97.9% (95.4–99.1), while the accordance between GLIM and PG-SGA was moderate (κ = 0.614). The performance of the GLIM worsened when MMR was excluded (κ = 0.515), with reduced sensitivity (50.2% (43.7–56.8)) and the same specificity (97.9% (95.4–99.1)). Including FFMI and ASMI by BIA can further improve the performance of GLIM than using CC alone (κ = 0.614 vs. κ = 0.565). Conclusions: It is important to include MMR in the GLIM framework. Using body composition measurement further improves the performance of the GLIM criteria than using anthropometric measurement alone.

IGF-I, Growth, and Body Composition in Preterm Infants up to Term Equivalent Age

Context There are concerns that a higher fat mass in the early life of preterm infants is associated with adverse cardiometabolic outcomes in young adulthood. Objective To investigate the role of IGF-I and growth in determining body composition of preterm infants at term equivalent age. Methods An observational study was conducted from August 2015 to August 2018. From birth to term equivalent age, IGF-I levels were measured bi-weekly and growth was assessed weekly. At term equivalent age, body composition was assessed through air displacement plethysmography; 65 infants with a gestational age of 24 to 32 weeks were assessed at term equivalent age, of whom 58 completed body composition measurement. The main outcome measures were fat (free) mass (g) and fat (free) mass percentage at term equivalent age. Results In the first month of life, each 0.1 nmol/L per week increase in IGF-I was associated with a 465 g (SE 125 g) increase in fat free mass. A greater increase in weight SDS in the first month of life was associated with a higher fat free mass percentage (B 200.9; 95% CI, 12.1-389.6). A higher head circumference SDS was associated with more fat free mass (r = 0.46; 95% CI, 0.21-0.65). However, a greater increase in weight SDS up to term equivalent age was associated with a lower fat free mass percentage (B −55.7, SE 9.4). Conclusion These findings suggest that impaired growth in the first month of life is associated with a less favorable body composition at term equivalent age.

Engaging Fathers to Improve Physical Activity and Nutrition in Themselves and in Their Preschool-Aged Children: The “Healthy Youngsters, Healthy Dads” Feasibility Trial

Background: Few lifestyle programs for young children have targeted fathers. This study examined the feasibility of a lifestyle intervention for fathers and their preschool-aged children. Method: A total of 24 father/preschool child dyads were recruited from Newcastle, Australia, into a single-arm, feasibility trial (baseline and 3-mo postbaseline assessments). The 9-session program aimed to improve physical activity and dietary habits of fathers and children. A priori feasibility benchmarks targeted recruitment (15 dyads), eligibility rate (>60%), attendance (80%), retention (≥85%), and program acceptability (≥4 out of 5). Acceptability of data collection procedures, research team program/resource management, home-program compliance, and preliminary intervention outcomes were also assessed. Results: Feasibility benchmarks were surpassed for recruitment (24 dyads), eligibility rate (61.5%), attendance (89%), retention (100%), and program acceptability (4.6 out of 5). Data collection procedures were acceptable. Challenges included mothers reporting their own dietary intake rather than their child’s, children moving during body composition measurement, and resetting pedometers. Resource and program management were excellent. Most families met home-program requirements (83%). Preliminary intervention outcomes were encouraging for fathers and children. Conclusion: Program feasibility was demonstrated by excellent recruitment, attendance, acceptability, retention, program administration, and promising preliminary intervention outcomes. A few data collection difficulties were identified. A larger scale efficacy trial is warranted.

Effects of Angiotensin (1-7) Expressing Lactobacillus and Exercise on Gut-Brain Axis in Aged Rats

Aging is associated with gut dysbiosis – a condition linked with altered central nervous system function (“gut-brain axis”). Age-related health benefits have been ascribed to the renin-angiotensin system, mediated partially via the angiotensin(1-7) axis. Research has shown exercise altering gut microbiota composition and function. This study explored the effects of a genetically modified probiotic expressing angiotensin (1-7) and exercise on the gut-brain axis. Sixty-two male F344/BN rats were randomized at 24-months-old to receive oral gavage of angiotensin (1-7) Lactobacillus paracasei (LP) or LP-A, wide-type LP, or control 3-times/week for 12 weeks; with or without exercise. Rats in exercise groups were walking on a treadmill 10-minutes/day for 5-days/week. Microbiome taxonomic analysis of fecal samples post intervention was performed via 16S-based PCR. A battery of behavior tests were performed before and after the intervention. PCoA revealed that groups differed in the overall fecal microbiota community structure by weighted UniFrac (p=0.034). Indices of alpha-diversity, including Shannon (p=0.02) and Simpson (p=0.019) indexes, displayed LP-A groups with more diverse microbiome than controls. Grip strength (p=0.042) and exercise tolerance (p&lt;0.001) tests showed exercise groups had more muscle strength and aerobic capacity than the sedentary groups. Exercise groups had more lean mass (p=0.019); both LP-A and LP groups had lower fat mass compared to the controls in body composition measurement. LP-A travelled longer distance in the central area than the control in the open field test showing reduced anxiety (p=0.029). Therefore, we conclude LP-A and exercise have distinct and possibly overlapping beneficial effects on the gut-brain axis.