Protective role of skeletal muscle mass against progression from metabolically healthy to unhealthy phenotype.
OBJECTIVE
Metabolically healthy individuals are known to be resistant to cardiovascular disease development. However, a considerable fraction of those individuals shows deteriorated metabolic health over time. Although skeletal muscle is the primary insulin-responsive target organ, a longitudinal investigation of the skeletal muscle mass in relation to the development of metabolically unhealthy phenotype has not been performed. We aimed to evaluate whether greater skeletal muscle mass is an independent protective factor for the development of metabolically unhealthy phenotype.


DESIGN, PARTICIPANTS AND MEASUREMENTS
We conducted a retrospective cohort study with 9033 metabolically healthy volunteers who underwent routine health examinations in 2012 and a follow-up examination in 2016. Obesity was defined as Asian-Pacific body mass index criterion ≥25 kg/m2 . Subjects with fewer than two risk factors (elevated blood pressure, triglyceride, glucose, high-sensitivity C-reactive protein, insulin resistance and decreased high-density lipoprotein cholesterol levels) were characterized as metabolically healthy using Wildman criteria.


RESULTS
At the 4-year follow-up, approximately one-fourth of the nonobese participants and half of the participants with obesity showed metabolic deterioration. In nonobese men and women, higher appendicular skeletal muscle mass (ASM)/weight at baseline was significantly associated with decreased risk of metabolic deterioration. Compared to the lowest quartile of ASM/weight, the adjusted odds ratios (95% confidence intervals) of the highest quartile were 0.68 (0.52-0.89) in nonobese men and 0.64 (0.46-0.90) in nonobese women. However, this association was not observed in obese subjects.


CONCLUSIONS
Greater skeletal muscle mass at baseline is significantly associated with maintenance of metabolically healthy status, especially in nonobese individuals.
['Lee|Min Jung|MJ|0000-0001-9090-5863', 'Kim|Eun-Hee|EH|', 'Bae|Sung-Jin|SJ|', 'Choe|Jaewon|J|', 'Jung|Chang Hee|CH|', 'Lee|Woo Je|WJ|', 'Kim|Hong-Kyu|HK|']
D000328:Adult D002318:Cardiovascular Diseases D015331:Cohort Studies D018450:Disease Progression D005260:Female D005500:Follow-Up Studies D006304:Health Status D006801:Humans D008297:Male D008875:Middle Aged D018482:Muscle, Skeletal D009765:Obesity D010641:Phenotype D012189:Retrospective Studies D012307:Risk Factors
cardiovascular diseases insulin resistance obesity phenotypes sarcopenia