Shu Mei Cheng

Gut-adipose tissue axis in hepatic fat accumulation in humans

BACKGROUND & AIMS Recent evidence suggests that in animals gut microbiota composition (GMC) affects the onset and progression of hepatic fat accumulation. The aim of this study was to investigate in humans whether subjects with high hepatic fat content (HHFC) differ in their GMC from those with low hepatic fat content (LHFC), and whether these differences are associated with body composition, biomarkers and abdominal adipose tissue inflammation. METHODS Hepatic fat content (HFC) was measured using proton magnetic resonance spectroscopy ((1)H MRS). Fecal GMC was profiled by 16S rRNA fluorescence in situ hybridization and flow cytometry. Adipose tissue gene expression was analyzed using Affymetrix microarrays and quantitative PCR. RESULTS The HHFC group had unfavorable GMC described by lower amount of Faecalibacterium prausnitzii (FPrau) (p<0.05) and relatively higher Enterobacteria than the LHFC group. Metabolically dysbiotic GMC associated with HOMA-IR and triglycerides (p<0.05 for both). Several inflammation-related adipose tissue genes were differentially expressed and correlated with HFC (p<0.05). In addition, the expression of certain genes correlated with GMC dysbiosis, i.e., low FPrau-to-Bacteroides ratio. CONCLUSIONS HHFC subjects differ unfavorably in their GMC from LHFC subjects. Adipose tissue inflammation may be an important link between GMC, metabolic disturbances, and hepatic fat accumulation.

Associations of disordered sleep with body fat distribution, physical activity and diet among overweight middle-aged men

This cross‐sectional study aimed to investigate whether body fat distribution, physical activity levels and dietary intakes are associated with insomnia and/or obstructive sleep apnea among overweight middle‐aged men. Participants were 211 Finnish men aged 30–65 years. Among the 163 overweight or obese participants, 40 had insomnia only, 23 had obstructive sleep apnea only, 24 had comorbid insomnia and obstructive sleep apnea and 76 were without sleep disorder. The remaining 48 participants had normal weight without sleep disorder. Fat mass, levels of physical activity and diet were assessed by dual‐energy X‐ray densitometry, physical activity questionnaire and 3‐day food diary, respectively. Among the overweight participants, we found that: (i) groups with sleep disorders had higher fat mass in trunk and android regions than the group without sleep disorder (P = 0.048–0.004); (ii) the insomnia‐only group showed a lower level of leisure‐time physical activity (436.9 versus 986.5 MET min week−1, P = 0.009) and higher intake of saturated fatty acids (14.8 versus 12.7 E%, P = 0.011) than the group without sleep disorder; and (iii) the comorbid group had a lower level of leisure‐time physical activity (344.4 versus 986.5 MET min week−1, P = 0.007) and lower folate intake (118.9 versus 152.1 μg, P = 0.002) than the group without sleep disorder, which were independent of body mass index. The results suggest that central obesity is associated with insomnia and/or obstructive sleep apnea. In addition, low levels of leisure‐time physical activity and poor dietary intakes are related to insomnia or comorbid insomnia and obstructive sleep apnea among overweight men.

Does Systemic Low-Grade Inflammation Associate With Fat Accumulation and Distribution? A 7-Year Follow-Up Study With Peripubertal Girls

CONTEXT Knowledge about the interrelationship between adiposity and systemic low-grade inflammation during pubertal growth is important in detecting early signs of obesity-related metabolic disorders. OBJECTIVE The objective of the study was to evaluate the developmental trajectories of fat mass (FM) and high sensitive C-reactive protein (hsCRP) levels and factors that could explain the relationship between FM and hsCRP in girls from prepuberty to early adulthood. DESIGN This was a 7.5-year longitudinal study. SETTING The study was conducted at the University of Jyväskylä Sports and Health Science laboratory. PARTICIPANTS Three hundred ninety-six healthy Finnish girls aged 11.2 ± 0.8 years participated in the study. METHODS Body composition was assessed by a dual-energy X-ray absorptiometry and serum concentrations of hsCRP, adipokines, and sex hormones by ELISA. RESULTS Both FM and hsCRP increased with age and had similar trajectories but different inter- and intravariance patterns. A joint analysis of fat distribution and hsCRP indicated that the linkage probabilities across different trajectory subgroups between regional FM and the corresponding hsCRP levels varied from 16% to 53%. In a longitudinal regression model, the common predictor for both FM and hsCRP was T (β = .065, P < 0.01, and β = -.213, P < 0.05, respectively) before menarche. Other factors predicting FM before menarche were SHBG (β = -.196, P < 0.01) and leptin (β = .381, P < .01); and after menarche hsCRP (β = .048, P < 0.01), T (β = .089, P < .01), leptin (β = .340, P < .01), and adiponectin (β = -.086, P < .05). Of the factors assessed, only FM was associated with hsCRP both before and after menarche (β =1.058, P < .01 and β =1.121, P < .01, respectively). CONCLUSIONS The differences in regional body fat depots and hsCRP levels in adulthood are largely established early in childhood. However, the intra- and interindividual variances differed between FM and hsCRP. FM explained the variance of hsCRP during pubertal growth, but the reverse was not true, which suggests that FM contributes to low-grade inflammation and not vice versa.

Does Serum 25-Hydroxyvitamin D Influence Muscle Development during Puberty in Girls? - A 7-Year Longitudinal Study

Vitamin D is well known for its regulatory role in calcium and phosphate homeostasis, but its role in muscle mass and strength during growth remains inconclusive. We explored the association of serum 25-hydroxyvitamin D (25(OH)D) with muscle development in girls from 11 to 18-years old. Whole body lean tissue mass (LMWB), appendicular lean mass (aLM), muscle cross-sectional area at the lower leg (mCSA), maximal voluntary contraction of elbow flexors (MVCelbow) and knee extensors (MVCknee) were assessed in 217 girls aged 10–13 years (at baseline), 215 in 2-year and 226 in 7.5-year follow-up. Serum concentration of 25(OH)D and intact parathyroid hormone (PTH) were analyzed retrospectively and girls were categorized according to their 25(OH)D levels (consistently insufficient 25(OH)D GLL <50 nmol/l and consistently sufficient GHH >50 nmol/l from baseline to 7-year follow-up). We found that 25(OH)D level declined until menarche (p<0.05) while LMWB, aLM, mCSA, MVCelbow and MVCknee continued to increase (p<0.001 for all) post menarche. At pre-menarche, the GLL (n = 34) had higher LMWB and aLM than the GHH (n = 21, p<0.05), while post-menarche the GHH (n = 15) had a greater catch-up gain in LMWB (p = 0.004), aLM (p = 0.001) and mCSA (p = 0.027) compared to the GLL (n = 65) over the first 2-year period. At the age of 18, no differences in muscle mass/strength between the low (n = 151) and high (n = 77) levels of 25(OH)D groups were found. This finding was independent of vitamin D receptor genotype and other confounders. In conclusion, our results showed that levels of 25(OH)D have no significant negative influence on the development of muscle mass and strength during pubertal growth both with longitudinal and cross-sectional comparison. On the contrary, our results suggest that the temporary negative association between 25(OH)D and muscle mass arises as a consequence of fast growth prior to menarche, and this negative association is diminished through catch-up growth after menarche.

What Makes a 97-Year-Old Man Cycle 5,000 km a Year?

Background: The nature versus nurture debate is one of the oldest issues in the study of longevity, health and successful aging. Objective: We present a 97-year-old man (I.K.) as an example of the effects of habitual exercise on the aging process. Methods: Extensive assessments included medical examinations, interviews, musculoskeletal structure, performance characteristics, cognitive function and gut microbiota composition. Results: I.K. suffers from iatrogenic hypogonadism, prostate cancer, hypothyroidism and a history of deep popliteal thrombosis. Notwithstanding, he cycles up to 5,000 km a year and participates in competitive sports. His musculoskeletal properties, athletic performance, cognitive function and gut microbiota are outstanding. Some traits even exceed those seen in middle-aged men. Conclusions: His long-term physically and intellectually active lifestyles combined with extensive social interactions have most likely contributed to his exercise capacity, despite his medical history.

Lactation, bone strength and reduced risk of bone fractures: reply to comment by Cure-Cure et al.

Dear Editor, Drs. Cure-Cure and Cure [1] have raised the important question of whether greater maternal bone size and bone strength due to prolonged lactation protects women from fragility fractures in the long run. We cannot answer this question at this time since the majority of the women in our study [2] were pre-menopausal. We will explore this issue later by following up this cohort. References