Physical Fitness Tests and Type 2 Diabetes Among Japanese: A Longitudinal Study From the Niigata Wellness Study

Associations of muscle mass and strength with new-onset diabetes among middle-aged and older adults: evidence from the China health and retirement longitudinal study (CHARLS)

BACKGROUND

The associations of muscle mass and strength with new-onset Type 2 diabetes mellitus (T2DM) remain controversial. We aimed to longitudinally evaluate muscle mass and strength in predicting T2DM among Chinese middle-aged and older adults.

METHODS

We enrolled 6033 participants aged ≥ 45 years from the China Health and Retirement Longitudinal Study (CHARLS), a cohort survey, between 2011 and 2012. The appendicular skeletal muscle mass (normalized by weight, ASM/BW%), relative hand grip strength (normalized by weight, HGS/BW), and five-repetition chair stand test (5CST). were all categorized into tertiles (lowest, middle, and highest groups) at baseline, respectively. Individuals were followed up until the occurrence of diabetes or the end of CHARLS 2018, whichever happened first. Cox proportional hazards models to calculate hazard ratios with 95% confidence intervals (CI) and mediation analysis were used.

RESULTS

During follow-up, 815 (13.5%) participants developed T2DM. After adjusting for covariates, lower ASW/BW% was not associated with a higher risk of diabetes. Compared with individuals in the highest tertile of HGS/BW, those in the lowest tertile had 1.296 (95%CI 1.073-1.567) higher risk of diabetes. Compared with individuals in the lowest tertile of 5CST, those in the highest tertile had 1.329 times (95%CI 1.106-1.596) higher risk of diabetes. By subgroup, both the lowest HGS/BW and highest 5CST were risk factors for diabetes among obesity. The mediation analysis revealed that the effect of HGS/BW on the risk of diabetes is mainly mediated by insulin resistance.

CONCLUSIONS

Lower muscle strength is associated with an increased risk of diabetes, especially in obese populations.

The Impact of Hand Strength on HbA1c, Body Mass Index and Body Composition by Group According to Sedentary Behaviour: Cross-Sectional Study in Japanese Patients with Type 2 Diabetes Mellitus

Background

The impact of hand strength in consideration of sedentary behaviour on diabetes management in patients with type 2 diabetes mellitus (T2DM) is unclear. The purpose of this study was to examine the impact of hand strength on HbA1c, body mass index (BMI) and body composition by group according to the duration of sedentary behaviour in Japanese patients with T2DM.

Methods

In this retrospective, cross-sectional, single-centre study, hand strength standardised by bodyweight (GS) and sedentary time (ST), were obtained and analysed in a total of 270 Japanese T2DM outpatients in 2021. After dividing the patients into four categories of median values (high and low GS, and long and short ST), odds ratios (ORs) for good control of HbA1c, BMI, waist circumference (WC) and intra-abdominal fat (IAF) were investigated using logistic regression models.

Results

The high GS/short ST group was found to have a significantly higher (OR = 2.01; 95% CI: 1.00, 4.03; P = 0.049) for controlled HbA1c compared with that of the low GS/long ST group. The high GS/short ST and the high GS/long ST groups had significantly higher ORs for controlled BMI, WC and IAF compared with the OR of the low GS/long ST group. In addition, the ORs were significantly increased with a positive trend in order from low GS/long ST, low GS/short ST, high GS/long ST, to high GS/short ST in all models (P < 0.001 for trend).

Conclusion

Hand strength, with modest effects from sedentary behaviour, could be helpful for diabetes management in T2DM patients.

Relationship between Handgrip Strength and Incident Diabetes in Korean Adults According to Gender: A Population-Based Prospective Cohort Study

(1) Background: Diabetes mellitus (DM) is a well-known disease that causes comorbidities such as chronic kidney disease (CKD) and cardiovascular disease. Therefore, it is necessary to develop diagnostic tools to prevent DM. Handgrip strength, a known diagnostic tool for sarcopenia, is a predictor of several diseases. However, the value of handgrip strength as an indicator of incident DM in Asian populations remains unknown. This study aimed to identify the relationship between handgrip strength and incidence of DM in Korean adults according to sex. (2) Methods: A total of 173,195 participants registered in a nationwide cohort were included in this study. After applying the exclusion criteria, 33,326 participants remained. DM occurred in 1473 individuals during the follow-up period (mean follow-up period, 4.1 years). To reduce the impact of body size, the study population was subdivided into quartiles of relative handgrip strength, defined as absolute handgrip strength divided by body mass index. Multivariate Cox regression analysis revealed that the relative handgrip strength was inversely associated with new-onset DM. (3) Results: Compared with the lowest quartile (Q1), the hazard ratios (HRs) [95% confidence intervals (CIs)] for new-onset DM for the highest quartiles (Q4) was 0.60 (0.43-0.84) in men and 0.72 (0.52-0.99) in women after adjusting for confounding factors. The incidence of DM decreased with the increase in the relative handgrip strength. These inverse relationships were statistically more significant in men than in women. (4) Conclusions: This novel study revealed that relative handgrip strength is related to incident DM in both men and women. Relative handgrip strength can be used as a practical tool to prevent DM. Regular measurement of handgrip strength can be used to detect DM.

A Simple Device for Measuring Sit-to-Stand Movements and Cardio-Metabolic Diseases: A Cross-Sectional Study in a Health Check-Up Population Over 20 Years Old

Introduction Several studies have reported the usefulness of measuring lower limb muscle strength through the motion of standing up using a reaction force measuring device positioned on the ground. There is inadequate information on the association between cardiovascular disease risk factors and ground reaction force (GRF) during standing up. Therefore, this study estimated the association between GRF by sit-to-stand movements and cardiovascular disease risk factors in a health check-up population. Methods This cross-sectional study included 1,182 healthy participants without chronic diseases who underwent periodic health check-ups from August 2019 to December 2020. The study included individuals aged ≥20 years who underwent a standing test from an initial seated position in a chair. A sit-to-stand force analyzer was used to measure GRF, and health status information was collected at enrollment. The relationships between blood test data and each measurement obtained from GRF measurements (forth/body mass (F/M), rate of forth development/body mass (RFD/M), and stable time) were parsed according to sex using linear regression analysis coordinated by age. GRF measurements and their relationships with cardiovascular disease risk factors were assessed using logistic regression analysis, adjusted for age and sex. Results A total of 1,182 participants was included in this study, with male participants accounting for 61.5%. The study participants had a median age of 57.0 years (IQR: 47.0-63.0). After adjusting for age, F/M was positively associated with high-density lipoprotein cholesterol in male (β=22.59, p<0.001) and female participants (β=20.35, p=0.011) and negatively associated with plasma glucose in male (β=-16.25, p=0.008) and female participants (β=-18.78, p=0.028). Stable time (time required to be stabilize after standing up movement) was positively associated with hemoglobin A1c levels in male (β=0.55, p=0.001) and female participants (β=0.56, p=0.036). Logistic regression analysis adjusted by age and sex showed that a lower F/M ratio was associated with hypertension, hyperlipidemia, and diabetes mellitus (adjusted odds ratio (aOR) =1.60, p=0.01; aOR=1.75, p=0.001; and aOR=2.23, p=0.002, respectively). Lower RFD/M was associated with hyperlipidemia and diabetes mellitus (aOR=1.46, p=0.013 and aOR=1.63, p=0.045, respectively). A shorter stable time was associated with diabetes mellitus (aOR=0.39, p<0.001). Conclusions These findings suggest that lower limb function impairment, as assessed via standing-up movements using a GRF-measuring device, may relate to cardiovascular disease. Further research is needed to confirm this association.

Utility of a Physical Fitness Score in Screening for Chronic Diseases

We developed a new Physical Score (PS) consisting of comprehensive physical fitness indicators and elucidated the association between the resultant PS and metabolic diseases, i.e., diabetes, hypertension, dyslipidemia, fatty liver, and metabolic syndrome (MetS), among Japanese. Analyzed were 49,850 persons (30,039 men) aged 30 to 69 y who underwent physical fitness tests. Principal component analysis was performed on the correlation matrix of the physical fitness test results (relative grip strength, single-leg balance with eyes closed, and forward bending) according to sex and age. We defined the PS as the first principal component score. A formula was developed for various age groups comprised of men and women from 30 to 69 years of age from which the PS for each age and sex was calculated. The PS for both men and women was normally distributed with a value of 0 ± 1.15-1.16. Multivariate logistic regression analysis showed that the risk of metabolic diseases increased approximately 1.1-1.6 times per each 1-point reduction in the PS. The association between PS and MetS was particularly strong in that a 1-point reduction in the PS increased the risk of MetS by 1.54 times (95% confidence interval 1.46 to 1.62) in men and by 1.21 times (1.15 to 1.28) in women. The association between a lower PS and disease risk was stronger in younger men for fatty liver and in older men for MetS. Conversely, in women, the association between a lower PS and disease risk was stronger in older women for fatty liver and in younger women for MetS. For diabetes, hypertension, and dyslipidemia, the change in the impact of PS reductions across age groups was small. The PS is a useful and simple non-invasive tool for screening Japanese people for metabolic diseases.

Feasibility and Reliability of Health-Related Physical Fitness Tests in Children and Adolescents with Hearing Impairment

Although research supports the feasibility and reliability of health-related physical fitness (HRPF) tests in typically developing children and adolescents, little is known regarding the feasibility and reliability of these tests for those with hearing impairments (HI). The aim of this study was to evaluate the feasibility and reliability of a HRPF test battery for children and adolescents with HI. A test-retest design with a one-week interval was conducted with 26 participants with HI (mean age: 12.7 ± 2.8 years; 9 male). The feasibility and reliability of seven field-based HRPF tests (i.e., body mass index, grip strength, standing long jump, vital capacity, long distance run, sit-and-reach, one leg stand) were evaluated. All the tests showed high feasibility (completion rate > 90%). Six tests indicated good to excellent test-retest reliability (all intraclass correlation coefficient [ICC] > 0.75) while the one leg stand test showed poor reliability (ICC = 0.36). Relatively large percentages of standard error of measurement (SEM%) and minimal detectable change (MDC%) were observed in the sit-and-reach test (SEM% = 52.4%, MDC% = 145.2%) and one leg stand test (SEM% = 107.9%, MDC% = 299.2%), whereas the rest of the tests demonstrated reasonable SEM% and MDC% values. Collectively, most of the tests can be feasibly and reliably used to assess HRPF for children and adolescents with HI.

Hand Grip Strength Relative to Waist Circumference as a Means to Identify Men and Women Possessing Intact Mobility in a Cohort of Older Adults with Type 2 Diabetes

Possessing intact mobility in older adults assures their continued independence. The early identification of reduced mobility in older adults with type 2 diabetes (T2DM) is paramount for preventing their future physical deterioration. Hand grip strength (HGS), relative to body size, is associated with mobility in older T2DM patients. This study aims to identify an HGS index that best identifies mobilityintact older T2DM patients, along with its optimal cut-off point. The baseline data are from a cohort of 122 older T2DM patients (59% women) (mean age of 70.2 ± 4.4 years). Three mobility tests encompassing three main mobility domains were measured, including usual gait speed (UGS), timed up and go (TUG), and a two-minute walk test (2MWT). Passing scores were defined as those either above the established cut-off points or above the 25th percentile of population norms. Passing all three tests was considered as possessing intact mobility. Receiver operating characteristic (ROC) curves of the most relevant HGS indices were constructed to determine the area under the curve (AUC) that best identifies patients with intact mobility. In a sample of 122 older adults with T2DM, 63.9% of women and 60% of men were found to possess intact mobility. HGS relative to waist circumference (WC) was found to have the strongest association with intact mobility, presenting the highest AUC in both men (0.78) and women (0.72) for discriminating mobility status, with an optimal cut-off of 0.355 (kg/cm) and 0.245 (kg/cm) in men and women, respectively. HGS relative to WC best differentiated between mobility-intact older adults with T2DM and those with mobility limitations, especially in men. Using HGS/WC as a simple and safe screening mode for mobility in a clinical setting could potentially identify older patients with T2DM that require therapeutic interventions.

Resistance exercise training-induced skeletal muscle strength provides protective effects on high-fat-diet-induced metabolic stress in mice

BACKGROUND

Resistance exercise training is known to improve metabolic disorders, such as obesity and type2 diabetes. In this study, we investigated whether the beneficial effects of resistance exercise training persisted even after the discontinuation of training with high-fat diet (HFD)-induced metabolic stress. We further evaluated whether the improvement in skeletal muscle strength and endurance by training were correlated with improved metabolism. Eight-week-old male C57BL/6N mice were divided into groups that remained sedentary or had access to daily resistance exercise via ladder climbing for 8 weeks. Trained and untrained mice were fed an HFD for 1 week after the exercise training intervention (n = 5-8 per group).

RESULTS

Resistance exercise-trained mice had a lean phenotype and counteracted diet-induced obesity and glucose tolerance, even after exercise cessation. Grip strength was significantly inversely correlated with the body weight, fat mass, and glucose tolerance. However, hanging time was significantly inversely correlated with body weight only.

CONCLUSIONS

These results have strong implications for the preventive effect of resistance exercise-induced metabolic improvement by enhancing skeletal muscle strength rather than endurance.

Combined association of walking pace and grip strength with incident type 2 diabetes

The current study aims to investigate the combined association of walking pace and grip strength with incident type 2 diabetes (T2D). A total of 205 738 participants (mean age 56.6 ± 8.1 years, 115 139 [56.0%] women) without diagnosed or unknown diabetes at baseline from the UK Biobank study were included in this prospective study. Walking pace was self-reported as slow, average, or brisk. Grip strength was measured using a dynamometer and classified as weak, average, and strong. The combined association of walking pace and grip strength with incident T2D was investigated using Cox-proportional hazards models with a 2-year landmark analysis. The additive interaction was conducted by estimating relative excess risk due to interaction (RERI). After the median follow-up period of 5.4 years (interquartile range: 4.8-6.5), 5082 (2.5%) participants were diagnosed with T2D. Compared to brisk-strong individuals (reference group), people who were slow-weak had a higher risk of T2D (hazard ratio: 1.64 [95% CI, 1.42-1.89]) after adjusting for all covariates. There were dose-response gradients across both walking pace and grip strength variables. There was a modest amount of negative additive interaction (RERI; -0.06 [95% CI, -0.16; -0.01]. To conclude, slower pace and weaker grip strength were associated with a higher risk of developing T2D, independent of sociodemographics, lifestyle, and adiposity. Combining walking pace and grip strength might be a practical approach to screening people who are at increased risk of developing T2D.

Association of Smartphone Use Duration with Physical Fitness among University Students: Focus on Strength and Flexibility

High-frequency smartphone use leads to physical inactivity and may consequently cause the loss of physical fitness. Although the relationship between smartphone usage and physical fitness has been investigated, most of these studies focused on partial physical fitness, and the evaluation of the duration of smartphone use was insufficient. Therefore, this study aimed to investigate the relationship between the time period of using smart phones and physical fitness in Chinese university students. In this cross-sectional study, 8977 college students (5189 men and 3788 women) were enrolled. The assessment of smartphone usage was performed using a self-reported questionnaire. Physical fitness was measured in a sports facility, consisting of grip strength, standing long jump, and sit-and-reach test. The post adjustment relationship between smartphone use duration and physical fitness was examined by using the ANCOVA test. In the final adjusted model, an inverse association was observed between the smartphone use duration and grip strength in male and female participants (p = 0.003 and <0.001, respectively). The smartphone use duration was also negatively associated with standing long jump in both sexes (p = 0.003 for male and = 0.026 for female). In male participants, the longer the period of using smartphones, the lower their flexibility (p = 0.026). In conclusion, this study investigated the association between the duration of smartphone use and physical fitness. The results showed that longer durations of smartphone use were associated with weaker grip strength, a shorter standing long jump, and lower flexibility. Controlling smartphone-use duration might be beneficial for physical fitness among university students.

The combination of cardiorespiratory fitness and muscular fitness, and prevalence of diabetes mellitus in middle-aged and older men: WASEDA'S Health Study

Background

Although the negative relationship between cardiorespiratory fitness (CRF) or muscular fitness and diabetes mellitus were respectively observed in many previous studies, there is still a lack of studies that include CRF and muscular fitness simultaneously. Therefore, this study aimed to investigate the relationship between the combination of CRF and muscular fitness and diabetes through a cross-sectional study. 

Methods

This study was part of WASEDA'S Health Study, a cohort study launched in 2014. We used a part of the baseline data collected for this study. Maximal exercise test using a cycle ergometer and leg extension power (LEP) test were respectively used to evaluate CRF and muscular fitness. Since LEP is affected by body weight, relative LEP (rLEP) which is LEP per body weight, was used as an index of muscular fitness. 796 men (56.5 ± 10.4 years old) who completed a medical examination and fitness tests, were divided into two groups based on CRF and rLEP, respectively. The prevalence of diabetes was collected based on a self-reported questionnaire or blood test. Odds ratios and 95% confidence intervals (CIs) for the prevalence of diabetes were obtained using logistic regression models while adjusting for age, body mass index, exercise habits, family history of diabetes, smoking habits, and drinking habits.

Results

55 (7%) participants had diabetes. Compared to participants with lower CRF or rLEP, the odds ratio (95% CIs) of diabetes in those with higher CRF or rLEP was 0.46 (0.21–0.98) or 0.34 (0.16–0.74), respectively. Furthermore, using the lower CRF and lower rLEP group as the reference, the odds ratio (95% CIs) for the lower CRF and higher rLEP group was 0.32 (0.12–0.88), and higher CRF and higher rLEP group was 0.21 (0.07–0.63), after adjusting for potential confounding factors.

Conclusions

CRF and rLEP have independent and joint inverse associations with diabetes prevalence. In addition, participants with high CRF and high rLEP had a lower prevalence of diabetes compared to those with only high CRF or only high rLEP.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-022-12971-x.

The Association of Smartphone Usage Duration with Physical Fitness among Chinese University Students

BACKGROUND

The use of smartphones has become increasingly prevalent in recent years, especially among the youth. However, smartphone overuse has been reported to be related to several negative mental and physical health outcomes. Although the association between smartphone use and physical fitness has been investigated in several studies, these studies only focused on specific elements of physical fitness, such as grip strength. In addition, evidence on young adults is limited. Thus, this study aimed to examine the association between the duration of smartphone use and physical fitness among Chinese university students.

METHODS

A total of 11,242 university students volunteered to participate in the study. The duration of smartphone use was assessed using a self-reported questionnaire. Physical fitness tests consisted of a 50-m sprint and vital capacity tests for both sexes, a 1000-m run and pull-up test for male students, and an 800-m run and sit-up test for female students.

RESULTS

The duration of smartphone use among the participants was 5.4 h/day for male students and 6.1 h/day for female students on average. After adjusting for confounding factors, in male students, a long duration of smartphone use was significantly associated with a slow 50 m sprint and 1000 m run time, lower pull-up times, and poor vital capacity (p = 0.004, 0.002, 0.002 and 0.040, respectively). In female students, a long duration of smartphone use was associated with a slow 800 m run time (p < 0.001).

CONCLUSION

This study found that longer duration of smartphone use was associated with lower physical fitness among Chinese university students. The duration of smartphone use may be an influencing factor for physical fitness.

Association between relative handgrip strength and abdominal obesity, type-2 diabetes and hypertension in a Mexican population

BACKGROUND

handgrip strength (HGS) is a health-status parameter associated with multicomorbidity in the adult population.

OBJECTIVE

the aim of the present study was to determine the association between HGS (i.e., absolute and relative) and abdominal obesity (AO), type-2 diabetes (T2D), and hypertension (HT), as well as to determine the association between low relative HGS with the presence of multicomorbidity (i.e., the co-occurrence of two or more comorbidities together) in a Mexican population.

METHODOLOGY

a cross-sectional study was carried out in 860 participants from the south of Mexico (661 women and 199 men). The age range evaluated was from 18 to 65 years. Assessments were made of sociodemographic data, clinical history, anthropometric parameters, and measurement of maximal HGS.

RESULTS

the regression models adjusted by age show that the presence of comorbidities (i.e., AO, HT and T2D) was linked negatively to HGS (i.e., absolute and relative). Moreover, in men, a low relative HGS in both hands reported an association with the presence of three simultaneous comorbidities (right, RR: 17.2, p < 0.001; left, RR: 11.92, p = 0.020). In women the same association was found (right, RR: 10.42, p < 0.001; left, RR: 9.90, p < 0.001).

CONCLUSION

lower levels of relative HGS were linked to the presence of simultaneous comorbidities (i.e., the joint presence of AO, T2D and HT). Furthermore, HGS (i.e., absolute and relative) presented an inverse association with individual anthropometric and clinical parameters related to cardiovascular risk in the Mexican population.

Leisure-time physical activity and incidence of objectively assessed hearing loss: The Niigata Wellness Study

Previous cohort study reported that high physical activity was associated with a low risk of self-reported hearing loss in women. However, no studies have examined the association between physical activity and the development of hearing loss as measured using an objective assessment of hearing loss in men and women. Here, we used cohort data to examine the association between leisure-time physical activity and incidence of objectively assessed hearing loss in men and women. Participants included 27 537 Japanese adults aged 20-80 years without hearing loss, who completed a self-administered physical activity questionnaire between April 2001 and March 2002. The participants were followed up for the development of hearing loss as measured by audiometry between April 2002 and March 2008. During follow-up, 3691 participants developed hearing loss. Compared with the none physical activity group, multivariable adjusted hazard ratios (HRs) for developing hearing loss were 0.93 (95% confidence interval (CI), 0.86-1.01) and 0.87 (0.81-0.95) for the medium (<525 MET-min/week) and high (≥525 MET-min/week) physical activity groups, respectively (p for trend = 0.001). The magnitude of risk reduction was slightly greater in vigorous-intensity activity than in moderate-intensity activity (p for interaction = 0.01). Analysis by sound frequency showed that the amount of physical activity was inversely associated with high frequency hearing loss development (p for trend <0.001), but not with low frequency hearing loss development (p for trend = 0.19). Higher level of leisure-time physical activity was associated with lower incidence of hearing loss, particularly for vigorous-intensity activities and high sound frequencies.

Handgrip strength as a simple measure for screening prediabetes and type 2 diabetes mellitus risk among adults in Malawi: A cross-sectional study

OBJECTIVE

Handgrip strength, a simple measure of muscle strength, has been reported as a predictor of both prediabetes and type 2 diabetes mellitus (T2DM) and has been suggested for screening prediabetes and T2DM risk. This study examined the relationship of handgrip strength with prediabetes and T2DM among rural- and urban-dwelling adults in Malawi.

METHODS

This was a cross-sectional study nested in a follow-up study of prediabetic and prehypertensive individuals identified during an extensive noncommunicable disease survey in Malawi. A total of 261 participants (women: 64%) were recruited. Univariate and multivariate binary logistic regression analyses were performed to examine the association of prediabetes and T2DM with relative handgrip strength.

RESULTS

The mean (SD) age of the participants was 49.7 (13.6) years, and 54.0% were between the ages of 40 and 59 years. The mean (SD) absolute handgrip strength and relative handgrip strength were 28.8 (7.3) kg and 1.16 (0.40) kg/BMI, respectively, and the mean relative handgrip strength differed significantly (p < 0.001) by T2DM status. In unadjusted model, the odds ratio (OR) of prediabetes and T2DM per unit increase in relative handgrip strength was 0.12 [95% CI; 0.04-0.33]. The result remained significant after adjusting for age (continuous), sex, place of study, hypertension, dyslipidaemia and level of education (aOR [95% CI]; 0.19 [0.03-0.95]).

CONCLUSIONS

The findings suggest that handgrip strength could be a relatively inexpensive, noninvasive measure for contributing to risk scores to identify high-risk individuals for screening diabetes in SSA.

What can hand grip strength tell us about type 2 diabetes?: mortality, morbidities and risk of diabetes

INTRODUCTION

Hand grip strength (HGS) has been determined as a simple and cost effective method for evaluating overall skeletal muscle strength and quality. It has been used in numerous clinical studies to examine the association between skeletal muscle and type 2 diabetes (T2D). Previous studies have shown that HGS is significantly associated with mortality and cardiovascular disease (CVD) in patients with T2D. As the prevalence of T2D has seen a steady increase globally, HGS measurement can be useful and essential in managing T2D.

AREAS COVERED

This narrative review summarizes the current evidence regarding the association between HGS and T2D. HGS has been considered a useful tool for identifying risks for T2D, CVD, and mortality and evaluating skeletal muscle strength and quality.

OPINION

HGS should be measured in all patients with T2D together with height, weight, and waist circumference. However, there is yet no standard method used in measuring for HGS. T2D patients with a low HGS can engage in resistance training more effectively with appropriate advice based on HGS. Future studies clarifying the genetic association between skeletal muscle and T2D are needed to provide individualized exercise therapy.

Observational study: handgrip strength, body composition and diabetes mellitus

Objective

Previous studies have shown that relative handgrip strength, handgrip measure divided by body mass index (BMI), affects the future onset of diabetes and prediabetes. However, fat free mass (FFM) has been suggested to adjust for this effect better than BMI. In this study, we examined applicability of models that adjusted handgrip-diabetes relationship with either BMI or FFM.

Results

Of 1940 participants (56.2% male, average (SD) age, 57.2 [11.2] years), 267 (13.8%) had diabetes (DM) and 912 (47.0%) had prediabetes (pre-DM). The average handgrip measure for men was 40.0 kg (tertile measures, 37.4 kg and 42.5 kg) and for women 24.2 kg (tertile measures, 22.6 kg and 25.7 kg). Among both sexes, the percentage of people unaffected by DM or pre-DM was highest in the strong handgrip group and lowest in the weak handgrip group. Analysis using binary logistic models showed that an increase in handgrip measure was associated with a decrease in the chance of having either pre-DM or DM. This effect was detected by both BMI models and FFM models, even after adjustment for medical and lifestyle factors. Either or both should be used depending on the research aims, setting and methods.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13104-021-05731-4.

Associations between relative grip strength and type 2 diabetes mellitus: The Yangpyeong cohort of the Korean genome and epidemiology study

Objective

To investigate the association between relative grip strength and the prevalence of type 2 diabetes mellitus (T2DM) independently and in combination with body mass index (BMI) in Korean adults.

Methods

The cross-sectional study includes 2,811 men and women (age 40 to 92 years old) with no history of heart disease, stroke, or cancer. Relative grip strength was measured by a handheld dynamometer and calculated by dividing absolute grip strength by body weight. Logistic regression analysis was used to calculate the odds ratios (ORs) and 95% confidence intervals (CIs) of T2DM by sex-specific quintiles of relative grip strength. In a joint analysis, participants were classified into 4 groups: “weak (lowest 20% quintile one) and normal weight (BMI <25.0 kg/m²)”, “weak and overweight/obese (BMI ≥25.0 kg/m²)”, “strong (upper 80% four quintiles) and normal weight” or “strong and overweight/obese”.

Results

Among the 2,811 participants, 371 were identified as having T2DM. Compared with the lowest quintile of relative grip strength (weakest), the ORs (95% CIs) of T2DM were 0.73 (0.53–1.02), 0.68 (0.48–0.97), 0.72 (0.50–1.03), and 0.48 (0.32–0.74) in upper quintiles two, three, four, and five, respectively, after adjusting for BMI and other potential confounders. In the joint analysis, compared with the “weak and overweight/obese” reference group, the odds of T2DM [ORs (95% CIs)] was lower in the “strong and overweight/obese” group [0.65 (0.46–0.92)] and the “strong and normal weight” group [0.49 (0.35–0.67)], after adjusting for potential confounders.

Conclusion

In this cross-sectional study, greater relative grip strength was associated with a lower prevalence of T2DM independent of BMI in Korean adults. Additional prospective studies are needed to determine whether a causal association exists between relative grip strength and T2DM prevalence considering BMI.

Association of a composite score of relative grip strength and timed up and go test with incident type 2 diabetes mellitus: Guangzhou Biobank Cohort Study

Background: We investigated association of a score incorporating relative grip strength (RGS) and timed up and go (TUG) test with incident type 2 diabetes mellitus (T2DM) in older Chinese.

Methods: Both RGS and TUG scores were classified into tertiles (0~2 points) and summed to yield RGS-TUG score, ranging from 0 to 4 points, with higher points indicating better physical function. Cox proportional hazards regression was used to analyze association of RGS-TUG score with incident T2DM.

Results: 3,892 participants without T2DM were followed up for an average of 3.6 years with 240 developing T2DM. After adjustment, those with the lowest RGS-TUG score, versus the highest, had higher fasting glucose, two-hour post-load glucose and glycosylated hemoglobin A1c, with β (95% confidence interval (CI)) being 0.21 (0.08, 0.33), 1.06 (0.69, 1.43) and 0.16 (0.06, 0.27), respectively. In participants with BMI of ≥25 kg/m2, those with the lowest RGS-TUG score showed a higher risk of T2DM (adjusted hazard ratio 3.01, 95% CI 1.04–8.69). No association was found for BMI of 18.5~<25 kg/m2 (P for interaction < 0.05).

Conclusions: This is the first study showing lower RGS-TUG score was associated with increased glycemia and incident T2DM in older people with overweight/obesity. The underlying mechanisms warrant further investigation.

A Prospective Cohort Study of Muscular and Performance Fitness and Risk of Hearing Loss: The Niigata Wellness Study

BACKGROUND

Several cross-sectional studies have linked higher physical fitness with better hearing sensitivity but have not established a causal relation; none have used a prospective design that is less susceptible to bias. We used a prospective cohort study to investigate the association between muscular and performance fitness and the incidence of hearing loss.

METHODS

A total of 21,907 participants without hearing loss received physical fitness assessments between April 2001 and March 2002. Muscular and performance fitness index, an age- and sex-specific summed z-score based on grip strength, vertical jump height, single-leg balance, forward bending, and whole-body reaction time was calculated. Participants were classified into quartiles according to the muscular and performance fitness index and each physical fitness test. They were followed up for the development of hearing loss, assessed by pure-tone audiometry at annual health examinations between April 2002 and March 2008. Hazard ratios and 95% confidence intervals for hearing loss incidence were estimated using Cox proportional hazards regression models.

RESULTS

During follow-up, 2765 participants developed hearing loss. The hazard ratios (95% confidence intervals) for developing hearing loss across the muscular and performance fitness index quartiles (lowest to highest) were 1.00 (reference), 0.88 (0.79-0.97), 0.83 (0.75-0.93), and 0.79 (0.71-0.88) (P_trend <.001). Among the various physical fitness components, a clear dose-response association with hearing loss incidence was observed for vertical jump height and single-leg balance (P_trend <.001 for both).

CONCLUSION

Higher muscular and performance fitness is associated with a lower incidence of hearing loss.

Handgrip strength-A risk indicator for type 2 diabetes: Systematic review and meta-analysis of observational cohort studies

AIMS

Evolving debate suggests that handgrip strength (HGS), a measure of muscular strength, might be associated with the risk of type 2 diabetes (T2D); however, the evidence is conflicting. Using a systematic review and meta-analysis of published observational cohort studies in general populations, we aimed to assess the association of HGS with the future risk of T2D.

METHODS

Relevant studies were sought from inception until April 2020 in MEDLINE, Embase, Web of Science, and manual search of relevant articles. Transformed or extracted relative risks (RRs) with 95% confidence intervals (CIs) comparing the top vs bottom thirds of HGS levels were pooled using random effects meta-analysis.

RESULTS

A total of 10 unique observational cohort studies comprising of 177 826 participants and >5167 T2D cases were eligible. The pooled multivariable RR (95% CI) for T2D comparing the top vs bottom thirds of HGS levels was 0.73 (0.63-0.84). This association was consistent across several relevant subgroups except for evidence of effect modification by sample size (P value for meta-regression <.001): evidence of an association in smaller studies (<250 events) 0.50 (0.40-0.63), with no significant association in bigger studies (≥250 events) 0.87 (0.73-1.05). There was no evidence of small study effects using formal tests such as funnel plots and Egger's regression symmetry test.

CONCLUSION

Pooled analysis of observational cohort studies suggests that HGS may be a risk indicator for T2D in the general population. The role of utilizing HGS measurements in T2D prevention strategies warrants further investigation.

Association of physical fitness and motor ability at young age with locomotive syndrome risk in middle-aged and older men: J-Fit+ Study

Background

Physical fitness and motor ability are associated with the incidence of locomotive syndrome (LS) in older adults. The relationships between physical fitness and motor ability at a young age to LS risk in later life remain unclear. This study examined the association between physical fitness and motor ability among university students and their risk of LS in middle and old age.

Methods

The participants were 231 male alumni aged 48–65 years from the Department of Physical Education of a university in Japan. Physical fitness and motor ability test results during their fourth year at the university were used. Physical fitness tests included the side-step test, vertical jump test, back muscle, grip strength, trunk lift, standing trunk flexion, and step-test. Motor ability was tested using the 50-m and 1500-m run, running long jump, hand-ball throw, and pull-up test. LS risk was assessed using a seven-question standardized self-administered Loco-check questionnaire. Participants were divided into three groups (low, medium, and high) based on physical fitness and motor ability test results at young age, and LS risk was assessed at an older age across the three groups using Cox proportional hazards models.

Results

From the 2017 follow-up survey, the median follow-up period was 37 years (interquartile range, 33–41), and LS risk was suspected for 31 (13.4%) participants. Better performance on the side-step test was associated with the reduced risk of LS (hazard ratio 0.32; 95% confidence interval, 0.101–0.983, P = 0.047).

Conclusions

Good agility (side-step test) at a young age may reduce the future risk of LS among middle-aged and older men.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-021-02047-7.

Skeletal Muscle and Metabolic Health: How Do We Increase Muscle Mass and Function in People with Type 2 Diabetes?

BACKGROUND

Whilst skeletal muscles' primary role is allowing movement, it has important metabolic roles, including in glycemic control. Indeed, evidence indicates that low muscle mass and function are associated with an increased risk of type 2 diabetes, highlighting its importance in the development of metabolic disease.

METHODS

In this mini-review, we detail the evidence highlighting the importance of muscle in type 2 diabetes and the efficacy of resistance exercise in improving glycemic control alongside our approach to increase uptake of such exercise in people with type 2 diabetes. This summary is based in the authors' knowledge of the filed supplemented by a Pubmed search using the terms "muscle," "glycemic control," "HbA1c," "type 2 diabetes," and "resistance exercise."

RESULTS

The main strategy to increases muscle mass is to perform resistance exercise and, although the quality of evidence is low, such exercise appears effective in reducing Glycated Haemoglobin (HbA1c) in people with type 2 diabetes. However, to increase participation we need to improve our understanding of barriers and facilitators to such exercise. Current data indicate that barriers are similar to those reported for aerobic exercise, with additional resistance exercise specific barriers of looking to muscular, increase risk of cardiovascular event, having access to specialized equipment and knowledge of how to use it.

CONCLUSIONS

The development of simple resistance exercises that can be performed anywhere, that use little or no equipment and are effective in reducing HbA1c will be, in our opinion, key to increasing the number of people with type 2 diabetes performing resistance exercise.

Normalized Hand Grip and Back Muscle Strength as Risk Factors for Incident Type 2 Diabetes Mellitus: 16 Years of Follow-Up in a Population-Based Cohort Study

PURPOSE

Muscle strength is associated with type 2 diabetes mellitus (T2DM). However, it is controversial whether muscle strength and normalized muscle strength is a risk factor for T2DM. Moreover, the relationship of back muscle strength (BMS) and incident T2DM has not been reported. In this study, we investigated the relationship between HGS, BMS, normalized HGS and BMS, and incident T2DM.

METHODS

A total of 2699 non-diabetes subjects aged 40-69 years (1313 women and 1386 men) in the Korean Genome and Epidemiology Study (KoGES) Ansan cohort were followed for 16 years. At the baseline and biennial follow-up visits, fasting glucose, postprandial 2-h glucose, clinical examinations, HGS, and BMS were measured by trained interviewers and examiners. HGS and BMS were measured at baseline. The relationships between incident T2DM, HGS, BMS, and normalized HGS and BMS were estimated using Cox proportional hazard regression models after adjusting for the confounding factors.

RESULTS

HGS and BMS were not associated with incident T2DM in multivariate analysis. However, the hazard ratio (HR) per one standard deviation (SD) increase in the body mass index (BMI), waist circumference (WC), waist-hip ratio (WHR)-normalized HGS, and BMS was associated with a lower risk for incident T2DM in both women and men after adjusting for the confounding factors (HR = 0.842-0.880-fold for women, p ≤ 0.015; HR = 0.887-0.903-fold for men, p ≤ 0.024). In the sub-analysis of menopause status, the HR per one SD increase in BMI, weight^2/3, WC, and WHR-normalized HGS was associated with a lower risk for incident T2DM in both pre- and post-menopausal women after adjusting for the confounding factors (HR = 0.860-0.820-fold for premenopausal, P ≤ 0.006; HR = 0.900-0.867-fold for postmenopausal, p ≤ 0.024). Additionally, we confirmed that the quartile group with higher muscle strength was associated with a lower risk for incident T2DM.

CONCLUSION

The present study suggested that normalized HGS and BMS were associated with a lower risk for the future development of T2DM. Moreover, weak muscle strength in premenopausal women may be the cause of T2DM. Further research is needed to determine whether efforts to improve muscle strength, such as exercise can reduce the risk of T2DM.

A Prospective Cohort Study of Muscular and Performance Fitness and Incident Glaucoma: The Niigata Wellness Study

BACKGROUND

To examine the association between muscular and performance fitness (MPF) and the incidence of glaucoma.

METHODS

A total of 27,051 glaucoma-free participants aged 20-87 years underwent physical fitness tests between April 2001 and March 2002. The MPF index was calculated using an age- and sex-specific summed z-score from grip strength, vertical jump, single-leg balance, forward bending, and whole-body reaction time. The participants were divided into quartiles according to the MPF index and each physical fitness test. Participants were followed up for the development of glaucoma, which was defined based on physician-diagnosed glaucoma at an annual health examination between April 2002 and March 2008. Hazard ratios for the incidence of glaucoma were estimated using Cox proportional hazards models.

RESULTS

During follow-up, 303 participants developed glaucoma. Compared with the lowest MPF index group, hazard ratio (95% confidence interval) of developing glaucoma was 0.64 (0.46-0.89) for the highest MPF index group (P for trend = .001). Vertical jump and whole-body reaction time were associated with incident glaucoma (P for trend = .01 and <.001, respectively). There were no associations between the other physical fitness tests and the incidence of glaucoma.

CONCLUSION

Higher MPF is associated with lower incidence of glaucoma.

Bipedal hopping as a new measure to detect subtle sensorimotor impairment in people with multiple sclerosis

BACKGROUND

Bipedal hopping has the potential to detect subtle multiple sclerosis (MS)-related impairments, especially among patients who "pass" typical movement tests. In this narrative review, we outline the biomechanics of bipedal hopping and propose its usefulness as a novel outcome measure for people with MS having mild disability.

METHODS

We summarize articles that (1) examined the biomechanics of jumping or hopping and (2) tested the validity and/or reliability of hopping tests. We consolidated consistencies and gaps in research and opportunities for future development of the bipedal hop test.

RESULTS

Bipedal hopping requires immense power, coordination, balance, and ability to reduce co-contraction; movement components typically affected by MS. These impairments can be measured and differentiated by examining specific variables, such as hop length (power), symmetry (coordination), center of pressure (balance), and coefficient of variability (co-contraction/spasticity). Bipedal hopping challenges these aspects of movement and exposes sensorimotor impairments that may not have been apparent during walking.

CONCLUSIONS

Testing of bipedal hopping on an instrumented walkway may detect and monitor sensorimotor control in people with MS who do not currently present with clinical deficits. Early measurement is imperative for precise rehabilitation prescription to slow disability progression prior to onset of measurable gait impairment.Implications for rehabilitationJumping and hopping tests detect lower limb and balance impairments in children, athletes, and older adults.Bipedal hop test measures multiple domains: power, coordination, balance, and muscle timing.Bipedal hop test may expose subtle sensorimotor impairments in people with multiple sclerosis.Multiple variables measured can discern type of sensorimotor impairment to direct personalized rehabilitation programs.

Effect of temporary housing on incidence of diabetes mellitus in survivors of a tsunami-stricken area in 2011 Japan disaster: a serial cross-sectional RIAS study

The association between incidence of diabetes mellitus (DM) and living conditions has not been studied after natural disasters. We compared the incidence of DM between individuals living in temporary housing (TH) and those living in other types of accommodation (non-TH) five years after the 2011 Great East Japan Earthquake. Longitudinal follow-up was conducted from 2011 to 2015 in a cohort of 7,491 residents of coastal communities in Iwate Prefecture directly impacted by the 2011 disaster (mean age, 61.6 years; men, 36.0%). We calculated the odds ratio of new onset of DM in the TH group (n = 2,372) compared with the non-TH group (n = 5,119) using discrete-time logit models stratified by sex and age classes (64 years or younger and older than 65 years). The TH group showed a significantly higher odds ratio (OR) for DM in men aged 64 years or younger (OR [95% confidence interval (CI)], 1.71 [1.03–2.85]; P-value = 0.040). In women, living conditions were not significantly associated DM. Survivors relocated to TH appeared to be at an increased risk of new onset DM.

Association between muscle strength and depressive symptoms among Chinese female college freshmen: a cross-sectional study

Background

Increased physical activity level is related to lower risk of depressive symptoms, and there is an inverse association between muscle strength and risk of depressive symptoms among the elderly. Although there is evidence of an inverse association between muscle strength and depressive symptoms, the relationship between these variables in a younger population is still unknown. This study aimed to examine the association between handgrip strength, a representative indicator of skeletal muscle strength, and the risk of depressive symptoms among Chinese female college freshmen.

Methods

A cross-sectional study was conducted among 867 participants aged between 16 and 23 years. Handgrip strength was measured with a handheld digital Smedley dynamometer, and handgrip strength relative to body weight (kg/kg) was calculated and was classified into tertiles as follows: low (0.32–0.50), medium (0.51–0.58), and high (0.59–0.94). Depressive symptoms were evaluated using the 20-item Zung self-rating depression scale (SDS), and three cutoff points were used to indicate different depression levels.

Results

We found that 10.7% of participants were classified as having severe depressive symptoms using an SDS score of 50 as the cutoff point. After adjusting for potential confounders, the adjusted odds ratios and 95% confidence intervals (CIs) for moderate-to-severe depressive symptoms across tertiles of the relative handgrip strength were 1.00 (reference) for tertile 1, 0.614 (0.353, 1.069) for tertile 2, and 0.537 (0.292, 0.988) for tertile 3 (P for trend = 0.041). The significant associations remained when other cutoff points (SDS scores: 48 or 45) were used. Interactions between handgrip strength and potential confounders for depressive symptoms in the final models were not significant.

Conclusions

Our findings indicate that handgrip strength is inversely and independently related to the risk of depressive symptoms among Chinese female college freshmen. The present findings can help develop an effective intervention strategy against depression. Further intervention studies are needed to explore the mechanisms underlying the effects of handgrip strength on depressive symptoms.

Physical Fitness and Dyslipidemia Among Japanese: A Cohort Study From the Niigata Wellness Study

BACKGROUND

Grip strength reflects systemic muscle strength and mass and is reportedly associated with various metabolic variables. However, its prognostic association with dyslipidemia is unknown. We examined the association of grip strength and other physical fitness markers with the incidence of dyslipidemia among Japanese adults.

METHODS

A total of 16,149 Japanese (6,208 women) individuals aged 20-92 years who underwent a physical fitness test between April 2001 and March 2002 were included in this cohort study. Grip strength, vertical jump, single-leg balance with eyes closed, forward bending, and whole-body reaction time were evaluated at baseline. Dyslipidemia was annually determined based on fasting serum lipid profiles and self-reported dyslipidemia from April 2001 to March 2008.

RESULTS

During the follow-up period, 4,458 (44.9%) men and 2,461 (39.6%) women developed dyslipidemia. A higher relative grip strength (grip strength/body mass index) was associated with a lower incidence of dyslipidemia among both men and women (P for trend <0.001). Compared with those for the first septile, the hazards ratios and 95% confidence intervals (CIs) for the seventh septile were 0.56 (95% CI, 0.50-0.63) for men and 0.69 (95% CI, 0.58-0.81) for women. Moreover, relative vertical jump (vertical jump strength/body mass index) was also inversely associated with the incidence of dyslipidemia among both men and women (P for trend <0.001). There was no association between other physical fitness and dyslipidemia among both men and women.

CONCLUSION

Relative grip strength and vertical jump may be useful risk markers of the incidence of dyslipidemia.

The association between frailty and incidence of dementia in Beijing: findings from 10/66 dementia research group population-based cohort study

BACKGROUND

The relationship between frailty and dementia is unclear and there are very few population-based studies regarding this issue in China. The purpose of this study is to estimate the association between frailty and incident dementia in China, and to explore different effects of frailty established by three definitions of frailty on dementia incidence.

METHODS

A five-year prospective cohort study was carried out in 2022 participants aged 65 years and over in urban and rural sites in Beijing, China. The participants were interviewed by trained community primary health care workers from 2004 to 2009. Frailty was defined using modified Fried frailty phenotype, physical frailty definition, and multidimensional frailty definition. Dementia was diagnosed using the 10/66 dementia criterion for calculating cumulative incidence. Both competing risk regression models and Cox proportional hazards models were applied to examine the associations between frailty at baseline and five-year cumulative incidence of dementia.

RESULTS

At the end of follow-up the five-year cumulative incidence rates of dementia with frailty and without frailty defined by the modified Fried frailty were 21.0% and 9.6%, those defined by the physical frailty were 19.9% and 9.0%, and those defined by the multidimensional frailty were 22.8% and 8.9%, respectively. Compared with non-frail participants, frail people had a higher risk of incident dementia using multidimensional frailty definition after adjusting covariates based on competing risk regression model (HR = 1.47, 95% CI 1.01~2.17) and Cox proportional hazards model (HR = 1.56, 95% CI 1.07~2.26). The association between frailty and incident dementia was statistically significant in participants in the upper three quartiles of age (aged 68 years and over) using the multidimensional frailty definition based on the competing risk regression model (HR = 1.61, 95% CI 1.06~2.43) and Cox proportional hazard model (HR = 1.76, 95% CI 1.19~2.61).

CONCLUSIONS

Multidimensional frailty may play an inherent role in incident dementia, especially in the people aged over 68, which is significant for distinguishing high risk people and determining secondary prevention strategies for dementia patients.

Simple-measured leg muscle strength and the prevalence of diabetes among Japanese males: a cross-sectional analysis of data from the Kameda health study

[Purpose] The aim of this study was to investigate the relationship between leg muscle strength, measured by a very simple one-leg stand-up test, and the prevalence of diabetes among Japanese males to raise awareness of diabetes prevention. [Participants and Methods] This cross-sectional analysis was conducted in 1,800 Japanese males (median [interquartile range] age, 61 [56–67] years) who completed health examinations and a one-leg stand-up test. The prevalence of diabetes was defined if any of the following conditions applied: 1) fasting blood glucose level more than 126 mg/dl, 2) two-hour blood glucose level more than 200 mg/dl (75-g oral glucose tolerance test), 3) HbA1c more than 6.5%, 4) diagnosed with diabetes by a physician, and/or 5) treated for diabetes. [Results] There were 490 participants with diabetes, and 517 participants were unable to complete the sit-to-stand task. When males, who could stand up, were used as a reference, the odds ratio for the prevalence of diabetes was significantly higher among those who were unable to stand up on neither leg than those who successfully stood up on both right and left legs after adjustment for covariates. [Conclusion] Low leg muscle strength, as measured by the one-leg stand-up test, was associated with a higher prevalence of diabetes among Japanese males. Because of its simplicity, this test could be useful detecting individuals who are at increased risk of developing diabetes.

Handgrip strength predicts new prediabetes cases among adults: A prospective cohort study

•

There was high prediabetes incidence among participants of medical examinations.

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Lower relative handgrip strength (HS) predicted higher prediabetes incidence risk.

•

Results significant in individuals < 40 and ≥ 40 years old.

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HS predicted lower prediabetes incidence risk among normal weight individuals.

Conventional risk factors for prediabetes and type 2 diabetes such as obesity do not completely explain the higher prevalence of prediabetes; therefore, research to investigate the role of other independent risk factors is required. A few cross-sectional studies have reported an association between muscle strength and prediabetes among normal-weight adults, but the longitudinal relationship of muscle strength with incident prediabetes among adults has not been reported. This prospective cohort study was conducted to investigate whether relative handgrip strength in adults predicted prediabetes incidence after 2 years of follow-up. The study was conducted in Ibaraki prefecture, Japan and recruited individuals without prediabetes and diabetes attending lifestyle related medical examinations between April 2016 and March 2017 (n = 2054). Individuals who came for the follow-up medical examinations between April 2018 and March 2019 were included in the analysis (n = 1075). One hundred sixty-nine individuals (15.7%) developed prediabetes after a mean follow-up of 24.2 months (SD = 1.9 months). Multivariable adjusted hazard ratios (aHR) of new prediabetes cases were calculated using Cox regression. Higher baseline relative handgrip strength predicted a lower risk (aHR [95% CI] = 0.38 [0.21–0.71] of prediabetes incidence among adults. Importantly, relative handgrip strength predicted new prediabetes cases among normal weight individuals (aHR [95% CI] = 0.39 [0.16–0.96]). The findings suggest that handgrip strength measurement is useful to identify individuals at high risk of newly diagnosed prediabetes, importantly, among normal weight individuals. The identified individuals may benefit from early intervention to reduce the risk of prediabetes.

Cardiorespiratory fitness, muscular strength and risk of type 2 diabetes: a systematic review and meta-analysis

AIMS/HYPOTHESIS

The study aimed to quantitatively summarise the dose-response relationships between cardiorespiratory fitness and muscular strength on the one hand and risk of type 2 diabetes on the other and estimate the hypothetical benefits associated with population-wide changes in the distribution of fitness.

METHODS

We performed a systematic review with meta-analysis. The PubMed and EMBASE electronic databases were searched from inception dates to 12 December 2018 for cohort studies examining the association of cardiorespiratory fitness or muscular strength with risk of incident type 2 diabetes in adults. The quality of included studies was evaluated using the Newcastle-Ottawa Scale.

RESULTS

Twenty-two studies of cardiorespiratory fitness and 13 studies of muscular strength were included in the systematic review with both exposures having ten estimates available for the primary adiposity- or body size-controlled meta-analysis. In random-effects meta-analysis including 40,286 incident cases of type 2 diabetes in 1,601,490 participants, each 1 metabolic equivalent (MET) higher cardiorespiratory fitness was associated with an 8% (95% CI 6%, 10%) lower RR of type 2 diabetes. The association was linear throughout the examined spectrum of cardiorespiratory fitness. In 39,233 cases and 1,713,468 participants each 1 SD higher muscular strength was associated with a 13% (95% CI 6%, 19%) lower RR of type 2 diabetes. We estimated that 4% to 21% of new annual cases of type 2 diabetes among 45-64-year-olds could be prevented by feasible and plausible population cardiorespiratory fitness changes.

CONCLUSIONS/INTERPRETATION

Relatively small increments in cardiorespiratory fitness and muscle strength were associated with clinically meaningful reductions in type 2 diabetes risk with indication of a linear dose-response relationship for cardiorespiratory fitness.

REGISTRATION

PROSPERO (CRD42017064526).

Decline in Handgrip Strength From Midlife to Late-Life is Associated With Dementia in a Japanese Community: The Hisayama Study

BACKGROUND

The association between decline in handgrip strength from midlife to late life and dementia is unclear.

METHODS

Japanese community-dwellers without dementia aged 60 to 79 years (ie, individuals in late life; mean age, 68 years) were followed for 24 years (1988-2012) (n = 1,055); 835 of them had participated in a health examination in 1973-1974 (mean age, 53 years), and these earlier data were used for the midlife analysis. Using a Cox proportional hazards model, we estimated the risk conferred by a decline in handgrip strength over a 15-year period (1973-74 to 1988) from midlife to late life on the development of total dementia, Alzheimer's disease (AD), and vascular dementia (VaD) over the late-life follow-up period from 1988 to 2012.

RESULTS

During the follow-up, 368 subjects experienced total dementia. The age- and sex-adjusted incidence of total dementia increased significantly with greater decline in handgrip strength (increased or unchanged handgrip strength [≥+0%] 25.1, mildly decreased [-14 to -1%] 28.4, and severely decreased [≤-15%] 38.9 per 1,000 person-years). A greater decline in handgrip strength was significantly associated with higher risk of total dementia after adjusting for potential confounding factors; subjects with severely decreased handgrip strength had 1.51-fold (95% confidence interval, 1.14-1.99, P < 0.01) increased risk of total dementia compared to those with increased or unchanged handgrip strength. Similar significant findings were observed for AD, but not for VaD.

CONCLUSIONS

Our findings suggest that a greater decline in handgrip strength from midlife to late life is an important indicator for late-life onset of dementia.