Trunk lean mass and its association with 4 different measures of thoracic kyphosis in older community dwelling persons

Muscle strength rather than appendicular skeletal muscle mass might affect spinal sagittal alignment, low back pain, and health-related quality of life

Sarcopenia is defined as decreasing in muscle strength and mass, and dynapenia is defined as decreasing in muscle strength and maintained muscle mass. This study elucidated the prevalence and characteristics of sarcopenia and dynapenia and evaluate in elderly spinal disorders patients. 1039 spinal disorders patients aged ≥ 65 years were included. We measured age, grip strength, muscle mass, spinal sagittal alignment parameters, low back pain (LBP) scores and health-related quality of life (HR-QoL) scores. Based on the previous reports, patients were categorised into normal group: NG, pre-sarcopenia group: PG, dynapenia group: DG, and sarcopenia group: SG. Pre-sarcopenia, dynapenia, and sarcopenia were found in 101 (9.7%), 249 (19.2%), and 91 (8.8%) patients, respectively. The spinal sagittal alignment parameters, trunk muscle mass, LBP, and HR-QoL scores were significantly worse in DG and SG compared with those in PG and NG. Spinal alignment, trunk muscle mass, and clinical outcomes, including LBP and HR-QoL scores, were maintained in the PG and poor in the DG and SG. Thus, intervention for muscle strength may be a treatment option for changes of spinal sagittal alignment and low back pain.

Sex differences between the relationship of trunk muscle mass and whole body sagittal plane alignment in older adults

BACKGROUND

This study aimed to clarify sex differences in the relationship between trunk muscle mass, aging, and whole-body sagittal alignment.

METHODS

Subjects aged 60-89 years who underwent musculoskeletal screening in 2018 were included in the study. Subject demographics, trunk muscle mass (TMM) measured by bioelectrical impedance analysis (BIA), and spinopelvic and lower extremity alignment parameters measured from standing radiographic images were investigated. Additionally, TMM was corrected for BMI (TMM/BMI). The relationship between trunk muscle and whole-body sagittal alignment was analyzed for each age group (young-old group (60-74 years) and old-old group (>75 years)) and sex.

RESULTS

A total of 281 (mean age 75.4 ± 6.7 years, 100 males and 181 females) were enrolled. The trunk muscle mass in both men and women significantly decreased with age. Regarding TMM/BMI, there was no significant difference in men, but there was a significant difference between females in the young-old and old-old groups (p < 0.001). TMM/BMI was significantly correlated with sagittal vertical axis (SVA) and knee flexion angle (KF) in both sexes. In females, TMM/BMI was significantly correlated with thoracic kyphosis in the young-old group, whereas in the old-old group, TMM/BMI was correlated with SVA, PI-LL, and KF.

CONCLUSIONS

TMM was related to trunk anteverion and lower extremity alignment in both sexes. However, the relationship between TMM on alignment differs between sexes. Thoracic hyperkyphosis in young-old adults indicated a decrease in muscle mass, which may be a sign of future malalignment.

Conjugated linoleic acid supplements preserve muscle in high-body-fat adults: A double-blind, randomized, placebo trial

BACKGROUND AND AIMS

Conjugated linoleic acid (CLA) has been used to improve body composition in weight management. However, clinical trial results are inconsistent and limited among Asians. We aimed to investigate the effect of CLA on body composition of Chinese adults with elevated body fat percentage.

METHODS AND RESULTS

In this double-blind, randomized, placebo-controlled trial, 66 Chinese adults (aged 18-45 years old, 37.9% male) with elevated body fat percentage were provided with 3.2 g/day CLA (n = 33) or 3.2 g/day placebo (sunflower oil; n = 33) for 12 weeks. Both groups received lifestyle counseling, featured with low fat and low sugar diet, and moderate physical activity. Body composition was measured using dual-energy X-ray absorptiometry at the baseline and end of the trial. Sixty-four participants finished this study. Compared with the placebo group, the CLA group showed increased trunk muscle mass (MM) (0.6 ± 1.7 vs. -0.3 ± 1.2 kg, P = 0.019). Among those with an adherence score higher than 0.80 (n = 56, 87.5%), a greater increase in both total and trunk MM was observed in the CLA group (both P < 0.05). Moreover, the effect on MM appeared to be more evident in men, those with a body mass index <25 kg/m², or those with higher self-rated physical activity.

CONCLUSIONS

In Chinese adults with elevated body fat percentage, 3.2 g/day CLA supplementation may be effective in preserving MM, especially in the trunk region.

REGISTRATION

This study was registered at ClinicalTrials.gov as NCT03915808 on April 9, 2019.

Identification of pleiotropic loci underlying hip bone mineral density and trunk lean mass

Bone mineral density (BMD) and lean body mass (LBM) not only have a considerable heritability each, but also are genetically correlated. However, common genetic determinants shared by both traits are largely unknown. In the present study, we performed a bivariate genome-wide association study (GWAS) meta-analysis of hip BMD and trunk lean mass (TLM) in 11,335 subjects from 6 samples, and performed replication in estimated heel BMD and TLM in 215,234 UK Biobank (UKB) participants. We identified 2 loci that nearly attained the genome-wide significance (GWS, p < 5.0 × 10^-8) level in the discovery GWAS meta-analysis and that were successfully replicated in the UKB sample: 11p15.2 (lead SNP rs12800228, discovery p = 2.88 × 10^-7, replication p = 1.95 × 10^-4) and 18q21.32 (rs489693, discovery p = 1.67 × 10^-7, replication p = 1.17 × 10^-3). The above 2 pleiotropic loci may play a pleiotropic role for hip BMD and TLM development. So our findings provide useful insights that further enhance our understanding of genetic interplay between BMD and LBM.

A Longitudinal Study of Trunk Muscle Properties and Severity of Thoracic Kyphosis in Women and Men: The Framingham Study

BACKGROUND

Cross-sectional studies suggest that trunk muscle morphology in the lumbar spine is an important determinant of kyphosis severity in older adults. The contribution of age-related changes in muscle morphology in the thoracic and lumbar spine to progression of kyphosis is not known. Our objective was to determine cross-sectional and longitudinal associations of thoracic and lumbar muscle size and density with kyphosis.

METHODS

Participants were 1,087 women and men (mean age: 61 years) of the Framingham Heart Study who underwent baseline and follow-up quantitative computed tomography (QCT) scanning 6 years apart. We used QCT scans to measure trunk muscle cross-sectional area (CSA, cm2) and density (HU) at the thoracic and lumbar spine and Cobb angle (degrees) from T4 to T12. Linear regression models estimated the association between muscle morphology and kyphosis.

RESULTS

At baseline, smaller muscle CSA and lower density of thoracic (but not lumbar) spine muscles were associated with a larger (worse) Cobb angle in women and men. For example, each standard deviation decrease in baseline thoracic paraspinal muscle CSA was associated with a larger baseline Cobb angle in women (3.7 degrees, 95% CI: 2.9, 4.5) and men (2.5 degrees, 95% CI: 1.6, 3.3). Longitudinal analyses showed that loss of muscle CSA and density at the thoracic and lumbar spine was not associated with progression of kyphosis.

CONCLUSIONS

Our findings suggest that kyphosis severity is related to smaller and lower density trunk muscles at the thoracic spine. Future studies are needed to determine how strengthening mid-back musculature alters muscle properties and contributes to preventing kyphosis progression.

ISSLS PRIZE IN CLINICAL SCIENCE 2019: clinical importance of trunk muscle mass for low back pain, spinal balance, and quality of life-a multicenter cross-sectional study

STUDY DESIGN

A multicenter cross-sectional study.

OBJECTIVES

To clarify the relationship of trunk muscle mass with low back pain, spinal sagittal balance, and quality of life. Few reports have investigated the relationship of trunk muscle mass with lumbar spine function and spinal balance, and the clinical significance of trunk muscle mass remains unclear.

METHODS

Patients attending spinal outpatient clinics at 10 different medical institutions were enrolled in this study. Patient demographics, trunk muscle mass and appendicular skeletal muscle mass (ASM) measured by bioelectrical impedance analysis (BIA), body mass index (BMI), Charlson Comorbidity Index (CCI), the Oswestry Disability Index (ODI), visual analog scale (VAS) for low back pain, sagittal vertical axis (SVA), and EuroQol 5 Dimension (EQ5D) score were investigated. Multivariate nonlinear regression analysis was used to investigate the association of trunk muscle mass with the ODI, VAS score, SVA, and EQ5D score.

RESULTS

Of 2551 eligible patients, 1738 (mean age 70.2 ± 11.0 years; 781 men and 957 women) were enrolled. Trunk muscle mass was significantly correlated with the ODI, VAS score, SVA, and EQ5D score (P < 0.001) when adjusted for age, sex, BMI, ASM, CCI, and history of lumbar surgery. Patient deterioration was associated with a decrease in trunk muscle mass, and the deterioration accelerated from approximately 23 kg.

CONCLUSIONS

Trunk muscle mass was significantly associated with the ODI, VAS score, SVA, and EQ5D score. Trunk muscle mass may assume an important role to elucidate and treat lumbar spinal dysfunction and spinal imbalance. These slides can be retrieved under Electronic Supplementary Material.

Association between visual classification of kyphosis and future ADL decline in community-dwelling elderly people: the Kurabuchi study

This cohort study conducted in Japan showed that severe age-related kyphosis was visually detected. The visual assessment of kyphosis was associated with declines in ADL, suggesting that we can easily identify people at high risk to develop future ADL reduction in the community setting.

PURPOSE

Age-related kyphosis is related with declines in activities of daily living (ADL). Its conventional diagnosis has been made by orthopedic surgeons and trained examiners using specialized equipment such as X-rays. We investigated whether visual classification of kyphosis by laypersons accurately predicted future ADL decline.

METHODS

This study was part of the Kurabuchi Study, a cohort study of community-dwelling elderly Japanese. Between 2009 and 2010, three layperson raters used reference illustrations to classify 532 participants without ADL decline at study baseline into four categories. Other examiners used conventional methods to assess kyphosis in the same participants: curve ruler, Spinal Mouse, and the block method. ADL decline was defined as the development of dependence according to the Katz Index, admission to a nursing home, or certification of long-term care need.

RESULTS

Thirty-five of the participants (6.6%) were classified with the most severe degree of kyphosis at baseline by visual assessment. Interrater agreement was high (Kappa = 0.73) for the most severe group. During 4.5 years of follow-up, 106 participants (19.9%) showed ADL decline. On the basis of visual assessment, the adjusted risk ratio for ADL decline among the participants with the most severe kyphosis was 2.6 (95% CI: 1.4-4.6). Assessments of kyphosis made with the Spinal Mouse also accurately predicted ADL decline.

CONCLUSIONS

Visual assessment of kyphosis predicted future declines in ADL in this study. Since our method requires no special tools or training, it may be useful for identifying those at high risk of ADL decline.

Patterns of menopausal hormone therapy use and hyperkyphosis in older women

OBJECTIVE

Hyperkyphosis, an exaggerated anterior curvature of the thoracic spine, is associated with poor physical function, falls, fractures, and earlier mortality. Low bone mineral density, bone loss, and vertebral fractures are strong risk factors for hyperkyphosis. Menopausal hormone therapy (HT) reverses bone loss, prevents vertebral fractures, and, therefore, we hypothesize, may reduce the risk for developing hyperkyphosis.

METHODS

We evaluated the cross-sectional association between Cobb angle of kyphosis from lateral spine radiographs and pattern of self-reported HT use during the prior 15-year period in 1,063 women from the Study of Osteoporotic Fractures.

RESULTS

Participants had a mean age of 83.7 ± 3.3 years and a mean Cobb angle of 51.3 ± 14.6°. Forty-six per cent of women were characterized as never-users of HT, 24% as remote past users, 17% as intermittent users, and 12% as continuous users. In minimally adjusted models, the mean Cobb angle was 4.0° less in continuous HT users compared with never-users (P = 0.01); however, in fully adjusted models, this association was attenuated to 2.8° (P = 0.06). Remote past HT users had 3.0° less kyphosis compared with never-users in minimally adjusted models (P = 0.01), attenuated to 2.8° less in fully adjusted models (P = 0.02). Intermittent users did not differ from never-users in degree of kyphosis.

CONCLUSIONS

Women reporting continuous or remote past HT use had less pronounced kyphosis than never-users by their mid-eighties, suggesting a possible role for HT in the prevention of age-related hyperkyphosis.

Kyphosis and incident falls among community-dwelling older adults

Hyperkyphosis commonly affects older persons and is associated with morbidity and mortality. Many have hypothesized that hyperkyphosis increases fall risk. Within this prospective study of older adults, kyphosis was significantly associated with incident falls over 1 year. Measures of hyperkyphosis could enhance falls risk assessments during primary care office visits.

INTRODUCTION

To determine the association between four measures of kyphosis and incident and injurious falls in older persons.

METHODS

Community-dwelling adults aged 65 and older (n = 72) residing in southern California were invited to participate in a prospective cohort study. Participants had kyphosis assessed four ways. Two standing measures included a flexicurve ruler placed against the back to derive a kyphotic index and the Debrunner kyphometer, a protractor used to measure the kyphotic angle in degrees. Two lying measures included the blocks method (number of 1.7 cm blocks needed to achieve a neutral head position while lying supine) and traditional Cobb angle calculation derived from DXA based lateral vertebral assessment. Baseline demographic, clinical, and other health information (including a timed up and go (TUG) test) were assessed at a clinic visit. Participants were followed monthly through email or postcard for 1 year, with falls outcomes confirmed through telephone interview.

RESULTS

Mean age was 77.8 (± 7.1) among the 52 women and 20 men. Over 12 months, 64% of participants experienced at least one incident fall and 35% experienced an injurious fall. Each standard deviation increase in kyphosis resulted in more than doubling the adjusted odds of an incident fall, even after adjusting for TUG. Odds of injurious falls were less consistent across measures; after adjusting for TUG, only the blocks method was associated with injurious falls.

CONCLUSIONS

Each kyphosis measure was independently associated with incident falls. Findings were inconsistent for injurious falls; the blocks measure suggested the strongest association. If these findings are replicated, the blocks measure could be incorporated into office visits as a quick and efficient tool to identify patients at increased fall risk.

The association of kyphosis assessed in supine and standing positions with future activities of daily living dependence: the Kurabuchi Study

We investigated the longitudinal association of noninvasively evaluated kyphotic posture with future dependence in activities of daily living and death in a community-dwelling older Japanese. We found that the association with outcomes varied according to the types of kyphotic posture.

INTRODUCTION

We have previously found an association between severe kyphosis and future dependence in activities of daily living (ADL) in people who manifest the condition in the supine position (structural curvature). However, because some people show severe kyphosis only in the standing position (postural curvature), we combined our noninvasively obtained kyphosis measurements from participants in the supine position (block method) with those obtained from participants in the standing position (kyphosis index) to determine whether not only structural curvature but also postural curvature is associated with ADL dependence and death.

METHODS

Between 2005 and 2006, we carried out health evaluations of adults aged 65 years or older in Kurabuchi Town, Japan: 792 participants (337 males, 455 females) who were independent in ADL at baseline and underwent evaluation of kyphotic posture were followed up until March 2014 (mean follow-up: 7.5 years). Participants who experienced one or more admissions to a nursing home, certification of a need for long-term care/support, or a decline in the Katz ADL Index during the follow-up period were defined as being dependent in ADL.

RESULTS

A flat back (straight spine in a standing position) and structural curvature were associated with future ADL dependence, but postural curvature was not. The multivariate-adjusted odds ratios (95% confidence interval) compared with physiological curvature (physiological curvature in a standing position) as the reference were 1.72 (1.04-2.86) for a flat back and 2.76 (1.59-4.79) for structural curvature. A weak association with death was observed in those with structural curvature.

CONCLUSIONS

Our results suggest that the prognoses of people with kyphosis differ according to the type of kyphotic posture.