Pedometer-determined physical activity level and change in arterial stiffness in Type 2 diabetes over 4 years

Systolic Blood Pressure and Longitudinal Progression of Arterial Stiffness: A Quantitative Meta-Analysis

Background

Arterial stiffness predicts the risk of cardiovascular events and all‐cause mortality and is associated with age and hypertension. However, the magnitude of the relationship between blood pressure (BP) and progression of arterial stiffness is unclear, limiting our understanding of how arterial stiffness mediates clinical effects of hypertension and planning of clinical trials.

Methods and Results

Medline and EMBASE were searched for prospective studies reporting linear models between baseline BP and progression of arterial stiffness, with and without adjustment for demographic characteristics and baseline stiffness. Standardized and unstandardized β coefficients for pulse wave velocity were combined by fixed and random effects meta‐analysis, weighted by the inverse variance. Of 566 fully reviewed articles from 30, 524 titles, 22 populations from 21 reports were included. In 9 cohorts, there were consistent, adjusted associations between baseline systolic BP and progression of arterial stiffness (11 781 patients; standardized β=0.041; 95% CI, 0.026–0.055; P<0.001; P value for heterogeneity=0.70), equivalent to a 1.14‐m/s increase in standard carotid‐femoral pulse wave velocity per decade per 20–mm Hg systolic BP, independent of age. Unstandardized, adjusted associations were similar (1762 patients; β=0.0047; 95% CI, 0.004–0.006; P<0.001; P value for heterogeneity=0.64), equivalent to a 0.94‐m/s increase per decade per 20–mm Hg systolic BP. In limited studies, standardized associations between mean BP and arterial stiffness progression were not significant and heterogeneous (913 patients; β=0.039; 95% CI, −0.008 to 0.086; P=0.11; P value for heterogeneity=0.03).

Conclusions

Baseline systolic BP was associated with a clinically important progression of arterial stiffness, independent of age, providing a reference for the potential effect of arterial stiffness in mediating changes in clinical outcomes associated with hypertension and providing a reference value to aid clinical trial design.

The impact of accelerometer wear location on the relationship between step counts and arterial stiffness in adults treated for hypertension and diabetes

OBJECTIVES

Accelerometer placement at the wrist is convenient and increasingly adopted despite less accurate physical activity (PA) measurement than with waist placement. Capitalizing on a study that started with wrist placement and shifted to waist placement, we compared associations between PA measures derived from different accelerometer locations with a responsive arterial health indicator, carotid-femoral pulse wave velocity (cfPWV).

DESIGN

Cross-sectional study.

METHODS

We previously demonstrated an inverse association between waist-worn pedometer-assessed step counts (Yamax SW-200, 7 days) and cfPWV (-0.20m/s, 95% CI -0.28, -0.12 per 1000 step/day increment) in 366 adults. Participants concurrently wore accelerometers (ActiGraph GT3X+), most at the waist but the first 46 at the wrist. We matched this subgroup with participants from the 'waist accelerometer' group (sex, age, and pedometer-assessed steps/day) and assessed associations with cfPWV (applanation tonometry, Sphygmocor) separately in each subgroup through linear regression models.

RESULTS

Compared to the waist group, wrist group participants had higher step counts (mean difference 3980 steps/day; 95% CI 2517, 5443), energy expenditure (967kcal/day, 95% CI 755, 1179), and moderate-to-vigorous-PA (138min; 95% CI 114, 162). Accelerometer-assessed step counts (waist) suggested an association with cfPWV (-0.28m/s, 95% CI -0.58, 0.01); but no relationship was apparent with wrist-assessed steps (0.02m/s, 95% CI -0.24, 0.27).

CONCLUSIONS

Waist but not wrist ActiGraph PA measures signal associations between PA and cfPWV. We urge researchers to consider the importance of wear location choice on relationships with health indicators.

Carotid femoral pulse wave velocity in type 2 diabetes and hypertension: capturing arterial health effects of step counts

Objective:

Optimal medication use obscures the impact of physical activity on traditional cardiometabolic risk factors. We evaluated the relationship between step counts and carotid-femoral pulse wave velocity (cfPWV), a summative risk indicator, in patients with type 2 diabetes and/or hypertension.

Research design and methods:

Three hundred and sixty-nine participants were recruited (outpatient clinics; Montreal, Quebec; 2011–2015). Physical activity (pedometer/accelerometer), cfPWV (applanation tonometry), and risk factors (A1C, Homeostatic Model Assessment–Insulin Resistance, blood pressure, lipid profiles) were evaluated. Linear regression models were constructed to quantify the relationship of steps/day with cfPWV.

Results:

The study population comprised 191 patients with type 2 diabetes and hypertension, 39 with type 2 diabetes, and 139 with hypertension (mean ± SD: age 59.6 ± 11.2 years; BMI 31.3 ± 4.8 kg/m²; 54.2% women). Blood pressure (125/77 ± 15/9 mmHg), A1C (diabetes: 7.7 ± 1.3%; 61 mmol/mol), and low-density lipoprotein cholesterol (diabetes: 2.19 ± 0.8 mmol/l; without diabetes: 3.13 ± 1.1mmol/l) were close to target. Participants averaged 5125 ± 2722 steps/day. Mean cfPWV was 9.8 ± 2.2 m/s. Steps correlated with cfPWV, but not with other risk factors. A 1000 steps/day increment was associated with a 0.1 m/s cfPWV decrement across adjusted models and in subgroup analysis by diabetes status. In a model adjusted for age, sex, BMI, ethnicity, immigrant status, employment, education, diabetes, hypertension, medication classes, the mean cfPWV decrement was 0.11 m/s (95% confidence interval −0.2, −0.02).

Conclusions:

cfPWV is responsive to step counts in patients who are well controlled on cardioprotective medications. This ability to capture the ‘added value’ of physical activity supports the emerging role of cfPWV in arterial health monitoring.

Physician step prescription and monitoring to improve ARTERial health (SMARTER): A randomized controlled trial in patients with type 2 diabetes and hypertension

AIMS

There are few proven strategies to enhance physical activity and cardiometabolic profiles in patients with type 2 diabetes and hypertension. We examined the effects of physician-delivered step count prescriptions and monitoring.

METHODS

Participants randomized to the active arm were provided with pedometers and they recorded step counts. Over a 1-year period, their physicians reviewed their records and provided a written step count prescription at each clinic visit. The overall goal was a 3000 steps/day increase over 1 year (individualized rate of increase). Control arm participants were advised to engage in physical activity 30 to 60 min/day. We evaluated effects on step counts, carotid femoral pulse wave velocity (cfPWV, primary) and other cardiometabolic indicators including haemoglobin A1c in diabetes (henceforth abbreviated as A1c) and Homeostasis Model Assessment-Insulin Resistance (HOMA-IR) in participants not receiving insulin therapy.

RESULTS

A total of 79% completed final evaluations (275/347; mean age, 60 years; SD, 11). Over 66% of participants had type 2 diabetes and over 90% had hypertension. There was a net 20% increase in steps/day in active vs control arm participants (1190; 95% CI, 550-1840). Changes in cfPWV were inconclusive; active vs control arm participants with type 2 diabetes experienced a decrease in A1c (-0.38%; 95% CI, -0.69 to -0.06). HOMA-IR also declined in the active arm vs the control arm (ie, assessed in all participants not treated with insulin; -0.96; 95% CI, -1.72 to -0.21).

CONCLUSIONS

A simple physician-delivered step count prescription strategy incorporated into routine clinical practice led to a net 20% increase in step counts; however, this was below the 3000 steps/day targeted increment. While conclusive effects on cfPWV were not observed, there were improvements in both A1c and insulin sensitivity. Future studies will evaluate an amplified intervention to increase impact.

Breaking sitting with light activities vs structured exercise: a randomised crossover study demonstrating benefits for glycaemic control and insulin sensitivity in type 2 diabetes

AIMS/HYPOTHESIS

We aimed to examine the effects of breaking sitting with standing and light-intensity walking vs an energy-matched bout of structured exercise on 24 h glucose levels and insulin resistance in patients with type 2 diabetes.

METHODS

In a randomised crossover study, 19 patients with type 2 diabetes (13 men/6 women, 63 ± 9 years old) who were not using insulin each followed three regimens under free-living conditions, each lasting 4 days: (1) Sitting: 4415 steps/day with 14 h sitting/day; (2) Exercise: 4823 steps/day with 1.1 h/day of sitting replaced by moderate- to vigorous-intensity cycling (at an intensity of 5.9 metabolic equivalents [METs]); and (3) Sit Less: 17,502 steps/day with 4.7 h/day of sitting replaced by standing and light-intensity walking (an additional 2.5 h and 2.2 h, respectively, compared with the hours spent doing these activities in the Sitting regimen). Blocked randomisation was performed using a block size of six regimen orders using sealed, non-translucent envelopes. Individuals who assessed the outcomes were blinded to group assignment. Meals were standardised during each intervention. Physical activity and glucose levels were assessed for 24 h/day by accelerometry (activPAL) and a glucose monitor (iPro2), respectively. The incremental AUC (iAUC) for 24 h glucose (primary outcome) and insulin resistance (HOMA2-IR) were assessed on days 4 and 5, respectively.

RESULTS

The iAUC for 24 h glucose (mean ± SEM) was significantly lower during the Sit Less intervention than in Sitting (1263 ± 189 min × mmol/l vs 1974 ± 324 min × mmol/l; p = 0.002), and was similar between Sit Less and Exercise (Exercise: 1383 ± 194 min × mmol/l; p = 0.499). Exercise failed to improve HOMA2-IR compared with Sitting (2.06 ± 0.28 vs 2.16 ± 0.26; p = 0.177). In contrast, Sit Less (1.89 ± 0.26) significantly reduced HOMA2-IR compared with Exercise (p = 0.015) as well as Sitting (p = 0.001).

CONCLUSIONS/INTERPRETATION

Breaking sitting with standing and light-intensity walking effectively improved 24 h glucose levels and improved insulin sensitivity in individuals with type 2 diabetes to a greater extent than structured exercise. Thus, our results suggest that breaking sitting with standing and light-intensity walking may be an alternative to structured exercise to promote glycaemic control in patients type 2 diabetes.

TRIAL REGISTRATION

Clinicaltrials.gov NCT02371239 FUNDING: : The study was supported by a Kootstra grant from Maastricht University Medical Centre⁺, and the Dutch Heart Foundation. Financial support was also provided by Novo Nordisk BV, and Medtronic and Roche made the equipment available for continuous glucose monitoring.

Psychosocial Variables Related to Why Women are Less Active than Men and Related Health Implications

This article reviews psychosocial influences on women’s participation in physical activity as they differ from men and how associated activity differences impact women’s risk for a number of chronic diseases. This topic directly aligns with the mission of this special edition related to disparities in women’s health as the typically lower level of physical activity in females directly impacts their health. On average, females participate in physical activity at lower rates than their male counterparts. These lower rates of physical activity are directly related to both incidence of and outcomes from cardiovascular disease, type 2 diabetes, and breast and gynecological cancers. The relationship between psychosocial factors that are understood to affect physical activity differs between men and women. Specifically, self-efficacy, social support, and motivation are empirically substantiated factors that found to impact physical activity participation among women differently than men. Understanding these relationships is integral to designing effective interventions to target physical activity participation in women so that the related health risks are adequately addressed.

Walking as a Contributor to Physical Activity in Healthy Older Adults: 2 Week Longitudinal Study Using Accelerometry and the Doubly Labeled Water Method

Background

Physical activity is recommended to promote healthy aging. Defining the importance of activities such as walking in achieving higher levels of physical activity might provide indications for interventions.

Objective

To describe the importance of walking in achieving higher levels of physical activity in older adults.

Methods

The study included 42 healthy subjects aged between 51 and 84 years (mean body mass index 25.6 kg/m² [SD 2.6]). Physical activity, walking, and nonwalking activity were monitored with an accelerometer for 2 weeks. Physical activity was quantified by accelerometer-derived activity counts. An algorithm based on template matching and signal power was developed to classify activity counts into nonwalking counts, short walk counts, and long walk counts. Additionally, in a subgroup of 31 subjects energy expenditure was measured using doubly labeled water to derive physical activity level (PAL).

Results

Subjects had a mean PAL of 1.84 (SD 0.19, range 1.43-2.36). About 20% of the activity time (21% [SD 8]) was spent walking, which accounted for about 40% of the total counts (43% [SD 11]). Short bouts composed 83% (SD 9) of walking time, providing 81% (SD 11) of walking counts. A stepwise regression model to predict PAL included nonwalking counts and short walk counts, explaining 58% of the variance of PAL (standard error of the estimate=0.12). Walking activities produced more counts per minute than nonwalking activities (P<.001). Long walks produced more counts per minute than short walks (P=.001). Nonwalking counts were independent of walking counts (r=−.05, P=.38).

Conclusions

Walking activities are a major contributor to physical activity in older adults. Walking activities occur at higher intensities than nonwalking activities, which might prevent individuals from engaging in more walking activity. Finally, subjects who engage in more walking activities do not tend to compensate by limiting nonwalking activities.

Trial Registration

ClinicalTrials.gov NCT01609764; https://clinicaltrials.gov/ct2/show/NCT01609764 (Archived by WebCite at http://www.webcitation.org/6grls0wAp)