Differential Age-Related Declines in Cardiorespiratory Fitness Between People With and Without Type 2 Diabetes Mellitus

Objective

To assess the extent to which the established age-related decline in cardiorespiratory fitness (CRF) is augmented in adult men with type 2 diabetes mellitus (T2DM).

Participants and Methods

This study used data from the Aerobics Center Longitudinal Study, conducted between September 18, 1974, and August 3, 2006, in primarily non-Hispanic white, middle-to-upper class adults. The analyses were restricted to adult men with complete data on age, CRF, and T2DM (35,307 participants). Quantile regression models were used to estimate age-related differences in CRF, estimated using a maximal treadmill test, between persons with and without T2DM. Smoking status and birth cohort served as covariates.

Results

Age-related declines in CRF were observed in men with and without T2DM. For men younger than 60 years, at low-mid percentiles of the CRF distribution the magnitude of the age-related decline in CRF was significantly higher (P-values=.00, .02) in men with T2DM than in those without T2DM. At upper percentiles, the decline with age between the 2 groups was virtually identical. Significant declines in CRF in men 45 years or younger were observed only at high levels of CRF for those without T2DM and at low levels of CRF for those with T2DM (P-values .00, .04).

Conclusion

This study reported that men younger than 60 years with T2DM at the low-mid CRF percentiles experience an accelerated age-related decline in CRF. Men younger than 60 years with T2DM exhibiting high levels of CRF experienced a decline in CRF comparable to men without T2DM. This study highlights the importance of incorporating sufficient levels of exercise or activity to maintain high CRF in men with T2DM.

The association of fitness and fatness with intermediate hyperglycemia incidence in women: A cohort study

The purpose of this study was to examine the associations of cardiorespiratory fitness, general adiposity, and central adiposity with incident intermediate hyperglycemia (IH) in women. We conducted a prospective cohort study of 1534 women aged 20-79 years old who had an annual health check-up with no history of major chronic diseases. At baseline, fitness was assessed by a Balke graded exercise test, and the estimated metabolic equivalents were used to create quartile groups. Women were also grouped based on their body mass index (<25 kg/m², 25-29.9 kg/m², and ≥ 30 kg/m²) and waist-to-height ratio (≥0.50 or < 0.50). Cox proportional hazards models were conducted to assess the association of fitness and fatness variables with incident IH defined as fasting glucose of 5.6-6.9 mmol/L. Overall, 18.1% (n = 277) of the women developed IH during an average follow-up of 5.06 years. Fitness, body mass index, and waist-to-height ratio at baseline were the independent predictors of the IH incidence in separate age-adjusted models; yet when all three variables were included in the same model along with confounding variables, only fitness remained significant and demonstrated a clear inverse association with incident IH (P-for-trend <0.001). Health promotion efforts should focus on improving fitness for the prevention of IH in women.

Resting Heart Rate and Risk of Cancer Mortality

BACKGROUND

Increased resting heart rate (RHR) is a predictor of mortality. RHR is influenced by cardiorespiratory fitness (CRF). Little is known about the combined associations of RHR and CRF on cancer mortality.

METHODS

50,108 men and women (mean age 43.8 years) were examined between 1974 and 2002 at the Cooper Clinic in Dallas, Texas. RHR was measured by electrocardiogram and categorized as <60, 60-69, 70-79, or ≥80 beats/minute. CRF was quantified by maximal treadmill test and dichotomized as unfit and fit corresponding to the lower 20% and the upper 80%, respectively, of the age- and sex-specific distribution of treadmill exercise duration. The National Death Index was used to ascertain vital status. Cox regression was used to compute HRs and 95% confidence intervals (CI) for cancer mortality across RHR categories.

RESULTS

During a mean follow-up of 15.0 ± 8.6 years, 1,090 cancer deaths occurred. Compared with RHR <60 beats/minute, individuals with RHR ≥80 beats/minute had a 35% increased risk of overall cancer mortality (HR, 1.35; 95% CI, 1.06-1.71) after adjusting for confounders, including CRF. Compared with "fit and RHR <80 beats/minute", HRs (95% CI) for cancer mortality were 1.41 (1.20-1.66), 1.51 (1.11-2.04), and 1.78 (1.30-2.43) in "unfit and RHR <80," "fit and RHR ≥80," and "unfit and RHR ≥80 beats/minute," respectively.

CONCLUSIONS

RHR ≥80 beats/minute is associated with an increased risk of overall cancer mortality. High CRF may help lower the risk of cancer mortality among those with high RHR.

IMPACT

RHR along with CRF may provide informative data about an individual's cancer mortality risk.

Resistance exercise, alone and in combination with aerobic exercise, and obesity in Dallas, Texas, US: A prospective cohort study

BACKGROUND

Obesity is a significant and growing public health problem in high-income countries. Little is known about the relationship between resistance exercise (RE), alone and in combination with aerobic exercise (AE), and the risk of developing obesity. The purpose of this prospective cohort study was to examine the associations between different amounts and frequencies of RE, independent of AE, and incident obesity.

METHODS AND FINDINGS

Participants were 11,938 healthy adults ages 18-89 years with a BMI < 30 kg/m2 at baseline who completed at least 2 clinical examinations during 1987-2005 as part of the Aerobics Center Longitudinal Study. Self-reported RE participation in minutes/week and days/week was collected from a standardized questionnaire. Incident obesity was defined as a BMI ≥ 30 kg/m2 at follow-up. Incident obesity was also defined by waist circumference (WC) > 102/88 cm for men/women and percent body fat (PBF) ≥ 25%/30% for men/women at follow-up in participants who were not obese by WC (n = 9,490) or PBF (n = 8,733) at baseline. During the average 6-year follow-up, 874 (7%), 726 (8%), and 1,683 (19%) developed obesity defined by BMI, WC, or PBF, respectively. Compared with no RE, 60-119 min/wk of RE was associated with 30%, 41%, and 31% reduced risk of obesity defined by BMI (hazard ratio [95% CI], 0.70 [0.54-0.92], p = 0.008), WC (0.59 [0.44-0.81], p < 0.001), and PBF (0.69 [0.57-0.83], p < 0.001), respectively, after adjusting for confounders including age, sex, examination year, smoking status, heavy alcohol consumption, hypertension, hypercholesterolemia, diabetes, and AE. Compared with not meeting the RE guidelines of ≥2 d/wk, meeting the RE guidelines was associated with 18%, 30%, and 30% reduced risk of obesity defined by BMI (hazard ratio [95% CI], 0.82 [0.69-0.97], p = 0.02), WC (0.70 [0.57-0.85], p < 0.001), and PBF (0.70 [0.62-0.79], p < 0.001), respectively. Compared with meeting neither guideline, meeting both the AE and RE guidelines was associated with the smallest hazard ratios for obesity. Limitations of this study include limited generalizability as participants were predominantly white men from middle to upper socioeconomic strata, use of self-reported RE, and lack of detailed diet data for the majority of participants.

CONCLUSIONS

In this study, we observed that RE was associated with a significantly reduced risk of obesity even after considering AE. However, meeting both the RE and AE guidelines was associated with the lowest risk of obesity.

The independent and joint associations among muscle strength, abdominal obesity and cardiometabolic variables among adults

The aim of the present study was to investigate the independent and joint associations among muscle strength (MS) and obesity with blood pressure, atherosclerosis, and laboratory markers. This was a cross-sectional study comprising a representative sample of 642 adults (men: 44.9%, 39.9 ± 11.2 years; women: 55.1%, 39.3 ± 11.1 years) from Florianópolis, Brazil. MS was assessed by handgrip strength. Obesity was defined as a Body Mass Index (BMI) ≥30.0 kg/m² and a waist circumference ≥80.0 cm in women and ≥90.0 cm in men. Clinical variables included systolic (SBP) and diastolic blood pressure (DBP), C-reactive protein (CRP), lipids, glucose metabolism markers and carotid intima-media thickness (IMT). Linear regression models stratified by sex and adjusted for confounders were used. Higher MS levels were related to lower CRP (up to 0.59 times lower), triglycerides (up to 0.33 times lower), HOMA-IR (up to 0.35 times lower), and higher HDL cholesterol (up to 5.2 mg/dL) levels among men. Among women, higher MS levels were related to lower SBP and DBP (up to -10.2 mmHg), CRP (up to 0.56 times lower), HOMA-IR (up to 0.27 times lower) and IMT (up to -4.8 × 10^-2 mm). In addition, MS was inversely related to triglycerides and HOMA-IR among obese men, inversely related to CRP among obese men and women, and inversely associated to DBP only among obese women. This population-based study corroborates findings from clinical studies suggesting that even among individuals with obesity, higher MS might help adults to reduce cardiometabolic risk. HighlightsMuscle strength levels were directly associated with better prognosis in relation to cardiometabolic variables in individuals with or without abdominal obesity.Among men with abdominal obesity, to have higher values of muscle strength were associated with lower values of diastolic blood pressure, C-reactive protein, triglycerides, cholesterol and HOMA-IR.Higher muscle strength levels were inversely associated with C-reactive protein among women with abdominal obesity; Higher muscle strength might help adults to reduce cardiometabolic risk.

Muscle strength cut-points for metabolic syndrome detection among adults and the elderly from Brazil

We aimed to determine cut-points for muscle strength based on metabolic syndrome diagnosis. This cross-sectional analysis comprised data from 2 cohorts in Brazil (EpiFloripa Adult, n = 626, 44.0 ± 11.1 years; EpiFloripa Aging, n = 365, 71.6 ± 6.1 years). Metabolic syndrome was assessed by relative handgrip strength (kgf/kg). Metabolic syndrome was defined as including ≥3 of the 5 metabolic abnormalities according to the Joint Interim Statement. Optimal cut-points from Receiver Operating Characteristic (ROC) curves were determined. Adjusted logistic regression was used to test the association between metabolic syndrome and the cut-points created. The cut-point identified for muscle strength was 1.07 kgf/kg (Youden index = 0.310; area under the curve (AUC)) = 0.693, 95% CI 0.614-0.764) for men and 0.73 kgf/kg (Youden index = 0.481; AUC = 0.768, 95% confidence interval (CI) = 0.709-0.821) for women (age group 25 to < 50 years). The best cut-points for men and women aged 50+ years were 0.99 kgf/kg (Youden index = 0.312; AUC = 0.651; 95% CI = 0.583-0.714) and 0.58 kgf/kg (Youden index = 0.378; AUC = 0.743; 95% CI = 0.696-0.786), respectively. Cut-points derived from ROC analysis have good discriminatory power for metabolic syndrome among adults aged 25 to <50 years but not for adults aged 50+ years. Novelty: First-line management recommendation for metabolic syndrome is lifestyle modification, including improvement of muscle strength. Cut-points for muscle strength levels according to sex and age range based on metabolic syndrome were created. Cut-points for muscle strength can assist in the identification of adults at risk for cardiometabolic disease.

Role of the active cycle of breathing technique combined with phonophoresis for the treatment of patients with chronic obstructive pulmonary disease (COPD): study protocol for a preliminary randomized controlled trial

Background

Chronic obstructive pulmonary disease (COPD) is a chronic inflammatory lung disease characterized by coughing, the production of excess sputum, and dyspnea. Patients with excessively thick sputum may have frequent attacks or develop more serious disease. The guidelines recommend airway clearance for patients with excessive sputum who are hospitalized with COPD. The active cycle of breathing technique is the most common non-pharmacological airway clearance technique used by physiotherapists. However, the effectiveness of the technique is not always guaranteed. Active cycle of breathing techniques require the initial dilution of the sputum, usually by inhalation drugs, which may have limited effects. Recent studies have found that phonophoresis decreases inflammation, suggesting the potential of the combined usage of active cycle of breathing techniques and phonophoresis. Therefore, the aim of this study is to explore the effectiveness and safety of combining active cycle of breathing technique and phonophoresis in treating COPD patients.

Methods and analysis

We propose a single-blind randomized controlled trial using 75 hospitalized patients diagnosed with COPD with excessive sputum production. The patients will be divided into three groups. The intervention group will receive active cycle of breathing techniques combined with phonophoresis. The two comparison groups will be treated with active cycle of breathing techniques and phonophoresis, respectively. The program will be implemented daily for 1 week. The primary outcomes will be changes in sputum viscosity and production, lung function, and pulse oximetry. Secondary outcomes include the assessment of COPD and anxiety, measured by the COPD Assessment Test scale and the Anxiety Inventory for Respiratory Disease, respectively; self-satisfaction; the degree of cooperation; and the length of hospital stay. All outcome measures, with the exception of sputum production and additional secondary outcomes, will be assessed at the commencement of the study and after 1 week’s intervention. Analysis of variance will be used to investigate differences between the groups, and a p-value of less than 0.05 (two-tailed) will be considered statistically significant.

Discussion

This study introduces a combination of active cycle of breathing techniques and phonophoresis to explore the impact of these interventions on patients hospitalized with COPD. If this combined intervention is shown to be effective, it may prove to be a better treatment for patients with COPD.

Trial registration

The trial was registered prospectively on the Chinese Clinical Trial Registry on 24 December 2019.ClinicalTrials.gov ChiCTR1900028506. Registered on December 2019.

The gene NtMYC2a acts as a 'master switch' in the regulation of JA-induced nicotine accumulation in tobacco

The biosynthesis and transport of nicotine has been shown to be coordinately upregulated by jasmonate (JA). MYC2, a member of basic helix-loop-helix (bHLH) transcription factor family, is well-documented as the core player in the JA signalling pathway to regulate diverse plant development processes. Four MYC2 genes were found in the tobacco genome, NtMYC2a/2b and 1a/1b. In this study, we tested whether one of them, NtMYC2a, acts as a 'master switch' in the regulation of nicotine biosynthesis and transport in tobacco. We generated NtMYC2a knockout tobacco plants using the CRISPR-Cas9 technique and analysed the effect of NtMYC2a knockout on expression of the nicotine biosynthesis genes (NtAO, NtQS, NtPMT1a, NtQPT2, NtODC2, NtMPO1, NtA622 and NtBBLa) and transport genes (NtMATE2 and NtJAT1), as well as leaf accumulation of nicotine in the NtMYC2a knockout plants. We found that all the nicotine biosynthesis and transport genes tested in this study were significantly downregulated (>50% reduction compared with wild-type control) in the NtMYC2a knockout plants. Moreover, the leaf nicotine content in knockout plants was dramatically reduced by ca 80% compared with the wild-type control. These results clearly show that NtMYC2a acts as a 'master switch' to coordinate JA-induced nicotine accumulation in tobacco and suggests that NtMYC2a might play an important role in tobacco nicotine-mediated defence against herbivory.

Temporal changes in personal activity intelligence and mortality: Data from the aerobics center longitudinal study

BACKGROUND

Personal activity intelligence (PAI) is a metric developed to simplify a physically active lifestyle for the participants. Regardless of following today's advice for physical activity, a PAI score ≥100 per week at baseline, an increase in PAI score, and a sustained high PAI score over time were found to delay premature cardiovascular disease (CVD) and all-cause mortality in a large population of Norwegians. However, the association between long-term temporal change in PAI and mortality in other populations have not been investigated.

OBJECTIVE

To test whether temporal change in PAI is associated with CVD and all-cause mortality in a large population from the United States.

METHODS

We studied 17,613 relatively healthy participants who received at least two medical examinations in the Aerobics Center Longitudinal Study between 1974 and 2002. The participant's weekly PAI scores were estimated twice, and adjusted hazard ratios (AHR) and 95% confidence intervals (CI) for CVD and all-cause mortality related to changes in PAI between baseline and last examination were assessed using Cox proportional hazard regression analyses.

RESULTS

During a median follow-up time of 9.3 years [interquartile range, 2.6-16.6; 181,765 person-years], there were 1144 deaths, including 400 CVD deaths. We observed an inverse linear association between change in PAI and risk of CVD mortality (P=0.007 for linear trend, and P=0.35 for quadratic trend). Compared to participants with zero PAI at both examinations, multivariable-adjusted analyses demonstrated that participants who maintained high PAI scores (≥100 PAI at both examinations) had a 51% reduced risk of CVD mortality [AHR, 0.49: 95% CI, 0.26-0.95)], and 42% reduced risk of all-cause mortality [AHR, 0.58: 95% CI, 0.41-0.83)]. For participants who increased their PAI scores over time (PAI score of zero at first examination and ≥100 at last examination), the AHRs were 0.75 (95% CI, 0.55-1.02) for CVD mortality, and 0.82 (95% CI, 0.69-0.99) for all-cause mortality. Participants who maintained high PAI score had 4.8 (95% CI, 3.3-6.4) years of life gained. For those who increased their PAI score over time, the corresponding years gained were 1.8 years (95% CI, 0.1-3.5).

CONCLUSION

Among relatively healthy participants, an increase in PAI and maintaining a high PAI score over time was associated with reduced risk of CVD and all-cause mortality.

CONDENSED ABSTRACT

Our objective was to investigate the association between temporal changes in PAI and mortality in a large population from the United States. In this prospective cohort study of 17,613 relatively healthy participants at baseline, maintaining a high PAI score and an increase in PAI score over an average period of 6.3 years was associated with a significant reduction in CVD and all-cause mortality. Based on our results, clinicians can easily recommend that patients obtain at least 100 PAI for most favourable protection against CVD- and all-cause mortality, but can also mention that significant benefits also occur at maintaining low-to-moderate PAI levels.

Semiparametric regression of the illness-death model with interval censored disease incidence time: An application to the ACLS data

To investigate the effect of fitness on cardiovascular disease and all-cause mortality using the Aerobics Center Longitudinal Study, we develop a semiparametric illness-death model account for intermittent observations of the cardiovascular disease incidence time and the right censored data of all-cause mortality. The main challenge in estimation is to handle the intermittent observations (interval censoring) of cardiovascular disease incidence time and we develop a semiparametric estimation method based on the expectation-maximization algorithm for a Markov illness-death regression model. The variance of the parameters is estimated using profile likelihood methods. The proposed method is evaluated using extensive simulation studies and illustrated with an application to the Aerobics Center Longitudinal Study data.

Waist circumference does not improve established cardiovascular disease risk prediction modeling

Despite considerable evidence demonstrating that waist circumference (WC) is independently associated with cardiovascular disease (CVD) and/or all-cause mortality, whether the addition of WC improves risk prediction models is unclear. The objective was to evaluate the improvement in risk prediction with the addition of WC, alone or in combination with BMI, to the Framingham Risk Score (FRS) and a population specific model. 34,377 men and 9,477 women aged 20 to 79 years who completed a baseline examination at the Cooper Clinic (Dallas, TX) during 1977–2003 and enrolled in the Aerobics Center Longitudinal Study (ACLS). WC was measured at the level of the umbilicus and expressed as a continuous variable. Deaths among participants were identified using the National Center for Health Statistics National Death Index. A total of 728 fatal cardiovascular disease (CVD) events occurred over a mean follow-up period of 13.1 ± 7.5 years. WC was significantly higher in CVD decedents (P = .002). The FRS C-statistic for fatal CVD in men was 0.836 (0.816–0.855) and 0.883 (0.851–0.915) in women. The addition of WC did not improve the C-statistic in men (0.831 (0.809–0.853)) or women (0.883 (0.850–0.916)). Similar findings were observed for non-fatal CVD and all-cause mortality, and when WC was added to a population specific model. Upon adding WC, the net-reclassification index was 0.024 with an integrated discrimination improvement of -0.0004. The addition of WC, alone or in combination with BMI, did not substantively improve risk prediction for CVD or all-cause mortality compared to the Framingham Risk Score or a population specific model.

CT and MRI features of giant cell tumours with prominent aneurysmal bone cysts in the extremities: a comparison with primary aneurysmal bone cysts

AIM

To test the hypothesis that computed tomography (CT) and magnetic resonance imaging (MRI) could help distinguish between giant cell tumours with prominent aneurysmal bone cysts (GABCs) and primary aneurysmal bone cysts (PABCs) of the extremities.

MATERIALS AND METHODS

CT and MRI features of 13 patients with GABCs and 13 patients with PABCs in the extremities were analysed retrospectively. The ages and sex of the patients were also recorded. Independent-samples t-tests were used for continuous variables and Fisher's exact tests were used for categorical variables to compare the differences between the two groups. Diagnostic accuracy, sensitivity, and interobserver agreement were calculated.

RESULTS

The average age of patients with GABCs (38.2±15.8 years) was higher than that of patients with PABCs (19.3±12.7 years; p=0.003). The transverse/longitudinal diameter ratio was different between GABCs (0.8±0.3) and PABCs (0.6±0.2; p=0.007). Subchondral bone involvement (92.3% versus 30.8%, p=0.004) and deep lobulation (38.5% versus 0%, p=0.039) were more likely to be noted in patients with GABCs. Surrounding blood vessels were identified in six cases of PABCs (6/13), but not in GABCs (p=0.015). The following characteristics were suggestive of GABCs, older patient age, higher transverse/longitudinal diameter ratio, subchondral bone involvement, and deep lobulation indicated a sensitivity of 84.6%, 76.9%, 75%, and 100%, and a specificity of 84.6%, 69.2%, 90%, and 61.9%, respectively. Conversely, surrounding blood vessels were suggestive of PABCs, with a sensitivity of 46.2% and specificity of 100%. The concordance between the two readers was moderate to nearly perfect.

CONCLUSION

Age, subchondral bone involvement, lobulation, transverse/longitudinal diameter ratio, and surrounding blood vessels can be used to distinguish GABCs from PABCs.

MiR-9 accelerates epithelial-mesenchymal transition of ovarian cancer cells via inhibiting e-cadherin

OBJECTIVE

To investigate the influence of micro-ribonucleic acid (miR)-9 on epithelial-mesenchymal transition (EMT) of ovarian cancer cells by targeted inhibition on E-cadherin (CDH1).

PATIENTS AND METHODS

The human ovarian cancer cells were cultured and miR-9 was repressed by inhibitors and overexpressed by miRNA mimics. The expression of EMT-related proteins was measured via Western blotting (WB). The action target of miR-9 was determined through the dual-luciferase reporter gene assay. The changes in protein levels were detected using WB.

RESULTS

The expression of miR-9 was markedly up-regulated in ovarian cancer tissues, that is, the expression level of serum miR-9 in ovarian cancer patients was higher than that in control group. After the inhibition of miR-9, the expression level of epithelial indicator CDH1 was increased, while that of interstitial indicator Vimentin was decreased. MiR-9 contained a complementary site in the 3'-untranslated region (UTR) of CDH1 messenger RNA (mRNA) and the mRNA and protein expressions of CDH1 in the cells were down-regulated obviously by miR-9 overexpression.

CONCLUSIONS

MiR-9 promotes the EMT of ovarian cancer cells through the targeted inhibition on CDH1.

Cardiorespiratory Fitness and the Risk of First Acute Myocardial Infarction: The HUNT Study

Background

The majority of studies evaluating cardiorespiratory fitness (CRF) as a cardiovascular risk factor use cardiovascular mortality and not cardiovascular disease events as the primary end point, and generally do not include women. The aim of this study was to investigate the association of estimated CRF (eCRF) with the risk of first acute myocardial infarction (AMI).

Methods and Results

We included 26 163 participants (51.5% women) from the HUNT study (Nord‐Trøndelag Health Study), with a mean age of 55.7 years, without cardiovascular disease at baseline. Baseline eCRF was grouped into tertiles. AMI was derived from hospital records and deaths from the Norwegian Cause of Death Registry. We used Fine and Gray regression modeling to estimate subdistribution hazards ratio (SHR) of AMI, accounting for competing risk of death. During a mean (range) follow‐up of 13 (0.02–15.40) years (347 462 person‐years), 1566 AMI events were recorded. In fully adjusted models men in the 2 highest eCRF had 4% (SHR: 0.96, 95% CI: 0.83–1.11) and 10% (SHR: 0.90, 95% CI: 0.77–1.05) lower SHR of AMI, respectively, when compared with men in the lowest tertile. The corresponding numbers in women were 12% (SHR: 0.88, 95% CI: 0.72–1.08) and 25% (SHR: 0.75, 95% CI: 0.60–0.95).

Conclusions

eCRF was inversely associated with risk of AMI event among women but not in men. Our data suggest that high eCRF may have substantial benefit in reducing the risk of AMI. Therefore, our data suggest that an increased focus on eCRF as a cardiovascular disease risk marker in middle‐aged and older adults is warranted.

Sodium butyrate relieves cerebral ischemia-reperfusion injury in mice by inhibiting JNK/STAT pathway

OBJECTIVE

The aim of this study was to investigate whether sodium butyrate (NaB) attenuated cerebral ischemia-reperfusion injury (IRI) in mice by inhibiting JNK/STAT pathway, thereby exerting a neuroprotective role.

MATERIALS AND METHODS

ICR mice were randomly assigned into five groups, including the sham group, the model group, the 1 mg/kg NaB group, the 5 mg/kg NaB group and the 10 mg/kg NaB group, respectively. IRI model was established in mice using the bilateral common carotid artery occlusion (BCCAO) method. Open-field test was performed to evaluate degree of IRI damage by recording central travel distance and central active time. The morphology of hippocampal neurons was observed by hematoxylin and eosin (HE) staining. TUNEL staining was conducted to detect apoptotic neurons in the brain of mice. Meanwhile, activities of superoxide dismutase (SOD) and malondialdehyde (MDA) in brain tissues of mice were determined by relative commercial kits. The expression levels of inflammatory factors in brain tissues of mice were accessed using enzyme-linked immunosorbent assay (ELISA). In addition, the protein expressions of Jak2 and STAT3 in brain tissues of mice were detected by Western blot.

RESULTS

10 mg/kg NaB treatment remarkably alleviated impaired neurological defect and hippocampal neurons, as well as significantly improved neuronal survival. Mice in the 10 mg/kg NaB group showed significantly lower central travel distance and shorter central active time than those in the sham group. In addition, 10 mg/kg NaB treatment markedly increased SOD activity, whereas significantly decreased MDA activity in IRI mice. Mice in the NaB treatment group showed significantly lower levels of IL-1β, TNF-α and IL-8. Meanwhile, TUNEL-positive neurons in mice of the NaB treatment group were remarkably fewer. In addition, the protein expression levels of Jak2 and STAT3 were obviously upregulated in IRI mice, which were significantly downregulated after 10 mg/kg NaB treatment.

CONCLUSIONS

Sodium butyrate exerts neuroprotective effects on cerebral ischemia-reperfusion injury by preventing oxidative stress, inflammatory response and neuronal apoptosis through inhibiting JNK/STAT pathway.

Association between change in maternal physical activity during pregnancy and infant size, in a sample overweight or obese women

Physical activity (PA) naturally declines during pregnancy and its effects on infant size are unclear, especially in overweight or obese pregnancies, a low-active subpopulation that tends deliver heavier infants. The objective of this study was to evaluate changes in prenatal PA and infant birthweight in a group of overweight or obese pregnant women. We employed a prospective analysis using data from a randomized controlled exercise trial (2001 to 2006) in sedentary, overweight or obese pregnant women in Michigan. Women with complete data on peak oxygen consumption, daily PA (via pedometers) and birthweight were included in the analyses. Change in PA was estimated via repeated measures analyses, and then its influence on infant birthweight was assessed via linear regression. Eighty-nine pregnant women were included and considered low-active (6,579.91 ± 2379.17 steps/day). PA declined from months 4 to 8 (-399.73 ± 371.38 steps∙day^-1∙month^-1). Analyses showed that the decline in PA (β = -0.28 g, 95%CI: -0.70, 0.25 g, p = .35) was not associated with birthweight. The findings of this study demonstrated that the decline in maternal PA during mid- to late-pregnancy, in overweight or obese women, was unrelated to infant birthweight. Future investigations should employ rigorous measurements of PA and infant anthropometry in this subpopulation.

Personal activity intelligence and mortality - Data from the Aerobics Center Longitudinal Study

IMPORTANCE

Personal activity intelligence (PAI) is a novel activity metric that can be integrated into self-assessment heart rate devices, and translates heart rate variations during exercise into a weekly score. Previous studies relating to PAI have been conducted in the same populations from Norway where the PAI metric has been derived, limiting generalizability of the results.

OBJECTIVE

To test whether PAI is associated with total and cause-specific mortality in a large cohort from the United States.

DESIGN

Aerobics Center Longitudinal Study (ACLS) - a prospective cohort between January 1974 and December 2002 with a mean follow-up of 14.5 years.

SETTING

Population-based.

PARTICIPANTS

56,175 relatively healthy participants (26.5% women) who underwent extensive preventive medical examinations at Cooper Clinic (Dallas, TX).

EXPOSURE

Personal activity intelligence (PAI) score per week was estimated and divided into 4 groups (PAI scores of 0, ≤50, 51-99, and ≥100).

MAIN OUTCOMES AND MEASURES

Total and cause-specific mortality.

RESULTS

During a median follow-up time of 14.9 (interquartile range, 6.7-21.4) years, there were 3434 total deaths including 1258 cardiovascular (CVD) deaths. Compared with the inactive (0 PAI) group, participants with a baseline weekly ≥100 PAI had lower risk of mortality: adjusted hazard ratio (AHR), 0.79: 95% CI, 0.71-0.87 for all-cause mortality, and AHR, 0.72: 95% CI, 0.60-0.87 for CVD mortality among men; AHR, 0.85: 95% CI, 0.64-1.12 for all-cause mortality, and AHR, 0.48: 95% CI, 0.26-0.91 for CVD mortality among women. For deaths from ischemic heart disease (IHD), PAI score ≥100 was associated with lower risk in both men and women (AHR, 0.70: 95% CI, 0.55-0.88). Obtaining ≥100 weekly PAI was also associated with significantly lower risk of CVD mortality in pre-specified age groups, and in participants with known CVD risk factors. Participants with ≥100 weekly PAI gained 4.2 (95% CI, 3.5-4.6) years of life when compared with those who were inactive at baseline.

CONCLUSIONS AND RELEVANCE

PAI is associated with long-term all-cause, CVD, and IHD, mortality. Clinicians and the general population can incorporate PAI recommendations and thresholds in their physical activity prescriptions and weekly physical activity assessments, respectively, to maximize health outcomes.

KEY POINTS

Question: What is the association between personal activity intelligence (PAI), a novel activity metric, and mortality in a large cohort from the United States?

FINDINGS

In this prospective study of 56,175 healthy participants at baseline, followed-up for a mean of 14.5 years, ≥100 PAI score/week was associated with significant 21% lower risk of all-cause and 30% lower risk of CVD mortality in comparison with inactive people. Participants with ≥100 PAI/week lived on average 4.2 years longer compared with inactive. Meaning: PAI is associated with long-term all-cause and CVD mortality. Clinicians and general population may incorporate PAI recommendations into weekly physical activity assessments to maximize CVD prevention.

Differential relationships between waist circumference and cardiorespiratory fitness among people with and without type 2 diabetes

Adults with type 2 diabetes mellitus tend to exhibit an increased level of central adiposity, augmenting their risk of further non-communicable diseases (NCDs). Importantly, consistent evidence demonstrates a significant, negative association between cardiorespiratory fitness (CRF) and waist circumference (WC). However, no previous studies have investigated differences in these CRF-related reductions in WC between adults with and without diabetes. This study used data from the Aerobic Center for Longitudinal Studies, conducted between 1970 and 2006 among predominately Non-Hispanic White, middle-to-upper class adults in Texas. Quantile regression models were used to estimate CRF-related differences in WC between persons with and without diabetes. Age, height, smoking status and birth cohort served as covariates. The analytic sample included 45901 adults. Significantly larger reductions in WC were observed among adults with diabetes as compared to without diabetes across all WC percentiles. Among males, high CRF levels were associated with significant reductions, as compared to their low-fit counterparts, in WC as large as 21.9 cm for adults without diabetes and as large as 27 cm for adults with diabetes. Among females, high CRF levels were associated with significant reductions, as compared to their low-fit counterparts, in WC as large as 22.3 and 30.0 cm for adults without and with diabetes, respectively. This study demonstrated that higher CRF is associated with significant reductions in WC, with greater magnitudes found among adults with diabetes, especially among the most centrally obese, highlighting the necessity of exercise prescription in this clinical population potentially leading to lower risks of future NCDs.

Weight Status and Sedentary Behavior of Alzheimer's Disease Caregivers

Objectives: In this study, we sought to characterize the weight status, sedentary behavior, and physical activity of caregivers of individuals with Alzheimer's disease. Methods: In 2014, we surveyed caregivers of individuals with Alzheimer's disease from the South Carolina Alzheimer's Disease Registry (N = 47) about their personal health behaviors. Additionally, a subset of individuals (N = 14) wore an accelerometer for 7 days. Results: Caregivers (N = 47) were mostly overweight or obese (85%) and self-reported a daily average sedentary time of 246.5 ± 203.0 minutes and 455.8 ± 291.4 minutes, as measured by 2 questionnaires. Objective measures indicated that persons spent an average of 769.4 ± 167.6 minutes per day (77.8% of their waking day) engaged in sedentary behavior. Conclusion: Given the negative health outcomes associated with both obesity and sedentary behavior, this is a vulnerable population that likely would benefit from interventions focused on weight management and reducing sedentary behavior.

Associations of Resistance Exercise with Cardiovascular Disease Morbidity and Mortality

PURPOSE

Resistance exercise (RE) can improve many cardiovascular disease (CVD) risk factors, but specific data on the effects on CVD events and mortality are lacking. We investigated the associations of RE with CVD and all-cause mortality and further examined the mediation effect of body mass index (BMI) between RE and CVD outcomes.

METHODS

We included 12,591 participants (mean age, 47 yr) who received at least two clinical examinations 1987-2006. RE was assessed by a self-reported medical history questionnaire.

RESULTS

During a mean follow-up of 5.4 and 10.5 yr, 205 total CVD events (morbidity and mortality combined) and 276 all-cause deaths occurred, respectively. Compared with no RE, weekly RE frequencies of one, two, three times or total amount of 1-59 min were associated with approximately 40%-70% decreased risk of total CVD events, independent of aerobic exercise (AE) (all P values <0.05). However, there was no significant risk reduction for higher weekly RE of more than four times or ≥60 min. Similar results were observed for CVD morbidity and all-cause mortality. In the stratified analyses by AE, weekly RE of one time or 1-59 min was associated with lower risks of total CVD events and CVD morbidity regardless of meeting the AE guidelines. Our mediation analysis showed that RE was associated with the risk of total CVD events in two ways: RE had a direct U-shaped association with CVD risk (P value for quadratic trend <0.001) and RE indirectly lowered CVD risk by decreasing BMI.

CONCLUSION

Even one time or less than 1 h·wk of RE, independent of AE, is associated with reduced risks of CVD and all-cause mortality. BMI mediates the association of RE with total CVD events.

Leisure-Time Running Reduces the Risk of Incident Type 2 Diabetes

OBJECTIVES

We examined the overall association as well as the dose-response relationship between leisure-time running and incident type 2 diabetes.

METHODS

Participants were 19,347 adults aged 18-100 years who were free of cardiovascular disease, cancer, and diabetes at baseline, and who received at least 2 extensive preventive medical examinations between 1974 and 2006. Running and other types of aerobic physical activity were assessed by self-reported leisure-time activities. Type 2 diabetes was defined as fasting glucose ≥126 mg/dL (7.0 mmol/L), physician diagnosis, or insulin use.

RESULTS

During an average follow-up of 6.5 years, 1015 adults developed type 2 diabetes. Approximately 29.5% of adults participated in leisure-time running at baseline. Runners had a 28% (hazard ratio [HR] 0.72; 95% confidence interval [CI], 0.62-0.84) lower risk of developing type 2 diabetes compared with nonrunners during follow-up. The HRs (95% CIs) of type 2 diabetes were 0.98 (0.75-1.28), 0.69 (0.51-0.92), 0.62 (0.45-0.85), 0.78 (0.59-1.04), and 0.57 (0.42-0.79) across quintiles of running time (minutes/week) compared with nonrunners after adjusting for potential confounders, including levels of nonrunning aerobic physical activity. Similar dose-response relationships between running distance (miles/week), frequency (times/week), total amount (MET-minutes/week), and speed (mph) were also observed.

CONCLUSIONS

Participating in leisure-time running is associated with a lower risk of developing type 2 diabetes in adults. Consistent linear dose-response relationships were observed between various running parameters and incident type 2 diabetes, supporting the prescription of running to prevent type 2 diabetes.

A varying-coefficient generalized odds rate model with time-varying exposure: An application to fitness and cardiovascular disease mortality

Varying-coefficient models have become a common tool to determine whether and how the association between an exposure and an outcome changes over a continuous measure. These models are complicated when the exposure itself is time-varying and subjected to measurement error. For example, it is well known that longitudinal physical fitness has an impact on cardiovascular disease (CVD) mortality. It is not known, however, how the effect of longitudinal physical fitness on CVD mortality varies with age. In this paper, we propose a varying-coefficient generalized odds rate model that allows flexible estimation of age-modified effects of longitudinal physical fitness on CVD mortality. In our model, the longitudinal physical fitness is measured with error and modeled using a mixed-effects model, and its associated age-varying coefficient function is represented by cubic B-splines. An expectation-maximization algorithm is developed to estimate the parameters in the joint models of longitudinal physical fitness and CVD mortality. A modified pseudoadaptive Gaussian-Hermite quadrature method is adopted to compute the integrals with respect to random effects involved in the E-step. The performance of the proposed method is evaluated through extensive simulation studies and is further illustrated with an application to cohort data from the Aerobic Center Longitudinal Study.