Bone marrow metabolism is affected by body weight and response to exercise training varies according to anatomical location

AIM

High body weight is a protective factor against osteoporosis, but obesity also suppresses bone metabolism and whole-body insulin sensitivity. However, the impact of body weight and regular training on bone marrow (BM) glucose metabolism is unclear. We studied the effects of regular exercise training on bone and BM metabolism in monozygotic twin pairs discordant for body weight.

METHODS

We recruited 12 monozygotic twin pairs (mean ± SD age 40.4 ± 4.5 years; body mass index 32.9 ± 7.6, mean difference between co-twins 7.6 kg/m2 ; eight female pairs). Ten pairs completed the 6-month long training intervention. We measured lumbar vertebral and femoral BM insulin-stimulated glucose uptake (GU) using 18 F-FDG positron emission tomography, lumbar spine bone mineral density and bone turnover markers.

RESULTS

At baseline, heavier co-twins had higher lumbar vertebral BM GU (p < .001) and lower bone turnover markers (all p < .01) compared with leaner co-twins but there was no significant difference in femoral BM GU, or bone mineral density. Training improved whole-body insulin sensitivity, aerobic capacity (both p < .05) and femoral BM GU (p = .008). The training response in lumbar vertebral BM GU was different between the groups (time × group, p = .02), as GU tended to decrease in heavier co-twins (p = .06) while there was no change in leaner co-twins.

CONCLUSIONS

In this study, regular exercise training increases femoral BM GU regardless of weight and genetics. Interestingly, lumbar vertebral BM GU is higher in participants with higher body weight, and training counteracts this effect in heavier co-twins even without reduction in weight. These data suggest that BM metabolism is altered by physical activity.

Stress, development and mental health study, the follow-up study of Finnish TAM cohort from adolescence to midlife: cohort profile

PURPOSE

This cohort profile describes the Stress, development and mental health study (TAM), which is a cohort study investigating risk and protective factors as well as longitudinal associations regarding mental health and well-being from adolescence to midlife. This interdisciplinary cohort study operates, for example, in the fields of public health, social medicine, psychiatry and the life course perspective.

PARTICIPANTS

In 1981 (n=2242, 98.0% of the target population), 1982 (n=2191, 95.6%) and 1983 (n=2194, 96.7%) during school classes, surveys were conducted to all Finnish-speaking pupils (mostly born 1967) in the Tampere region in Finland. Participants of the school study at age 16 in 1983 (n=2194) comprised the base population for the longitudinal data and were followed-up using postal questionnaires in the years 1989, 1999, 2009 and 2019 at ages 22 (n=1656, 75.5% of the age 16 participants), 32 (n=1471, 67.0%), 42 (n=1334, 60.8%) and 52 (n=1160, 52.9%).

FINDINGS TO DATE

The self-reported questionnaires include information on physical and mental health (eg, depression and mood disorders, anxiety disorders), health behaviour and substance misuse (eg, alcohol, tobacco and exercise), socioeconomic conditions, psychosocial resources (eg, self-esteem), social relationships and support, life events, etc. The numerous studies published to date have examined mental health and various factors from several perspectives such as risk and protective factors, individual developmental paths (eg, trajectories) and pathway models (mediation and moderation).

FUTURE PLANS

Current and future research areas include, for example, longitudinal associations between mental health (eg, depressive symptoms, self-esteem) and (1) substance use (alcohol and tobacco), (2) family transitions (eg, parenthood, relationship status) and (3) retirement. Next follow-up is planned to be conducted at the latest at age 62 in 2029. Before that it is possible to link the data with cause-of-death register.