Electrocardiographic markers in patients with type 2 diabetes and the role of diabetes duration

BACKGROUND

The association between type 2 diabetes and electrocardiographic (ECG) markers are incompletely explored and the dependence on diabetes duration is largely unknown. We aimed to investigate the electrocardiographic (ECG) changes associated with type 2 diabetes over time.

METHODS

In this cross-sectional study, we matched people with type 2 diabetes 1:1 on sex, age, and body mass index with people without diabetes from the general population. We regressed ECG markers with the presence of diabetes and the duration of clinical diabetes, respectively, adjusted for sex, age, body mass index, smoking, heart rate, diabetes medication, renal function, hypertension, and myocardial infarction.

RESULTS

We matched 988 people with type 2 diabetes (332, 34% females) with as many controls. Heart rate was 8 bpm higher (p < 0.001) in people with vs. without type 2 diabetes, but the difference declined with increasing diabetes duration. For most depolarization markers, the difference between people with and without type 2 diabetes increased progressively with diabetes duration. On average, R-wave amplitude was 6 mm lower in lead V5 (p < 0.001), P-wave duration was 5 ms shorter (p < 0.001) and QRS duration was 3 ms (p = 0.03). Among repolarization markers, T-wave amplitude (measured in V5) was lower in patients with type 2 diabetes (1 mm lower, p < 0.001) and the QRS-T angle was 10 degrees wider (p = 0.002). We observed no association between diabetes duration and repolarization markers.

CONCLUSIONS

Type 2 diabetes was independently associated with electrocardiographic depolarization and repolarization changes. Differences in depolarization markers, but not repolarization markers, increased with increasing diabetes duration.

Predictive value of attended automated office blood pressure and resting pulse rate for mortality in community-dwelling octogenarians: Minhang study

Systolic blood pressure (SBP) and resting pulse rate (RPR) have been linked to mortality and cardiovascular events in younger population. Till now, no studies simultaneously investigate the non-linear association of SBP and RPR with all-cause and cardiovascular mortality among population aged 80 and older. Data of 2828 eligible participants were selected from electronic health records linked attended automated office blood pressure measurement system. The dose-response relationship between the SBP, RPR, and the risk of all-cause and cardiovascular mortality was analyzed by Cox model with restricted cubic splines. During the 3.6-year follow-up, 442 deaths occurred. Comparing with the optimal SBP (117-145 mmHg), the lower (HR: 1.39, 95% CI: 1.07-1.81) and higher SBP (HR: 1.34, 95% CI: 1.08-1.65) were significantly associated with an increasing risk of all-cause mortality. The higher SBP (>144 mmHg) was associated with cardiovascular mortality, with the HR (95% CI) as 1.51 (1.07-2.12). The faster RPR showed the higher risk of all-cause (HR: 1.36, 95% CI: 1.05-1.76) and cardiovascular (HR: 1.51, 95% CI: 1.07-2.13) mortality. We found both higher SBP and faster RPR were independently associated with all-cause and cardiovascular mortality, and lower SBP was only associated with the increased risk of all-cause mortality in oldest old community-dwelling Chinese population. Our results demonstrate the prognostic importance of both SBP and RPR in the elderly.

The Danger of Being Too Sympathetic: Norepinephrine in Alzheimer's Disease and Graying of Hair

Although alterations in the sympathetic nervous system (SNS) with age have been reported, and serious degenerative diseases of the autonomic nervous system such as multiple system atrophy are more likely to strike older people, connections between dysregulated adrenergic receptors and age-associated diseases and phenotypes have not been well studied. Two recent reports suggest that SNS may be more closely connected than previously appreciated. First, low nanomolar concentrations of Alzheimer's disease (AD)-associated Aβ42-amyloid oligomers alter signaling by SNS neurotransmitter norepinephrine (NE) to sufficiently activate kinase GSK3β to hyperphosphorylate tau, a key mediator of neurotoxicity in AD. Connecting beta-amyloid to tau in AD has been a key quest in understanding AD and developing therapeutics. The α₂ adrenergic receptor inhibitory drug idazoxan reduces GSK3β activity and tau phosphorylation in AD mice with improved cognitive function, even in the presence of beta-amyloid deposits. In this study, SNS activation in the brain coupled with problematic Aβ42-amyloid oligomers result in serious consequences that can be ameliorated by reducing SNS signaling. A second example of the detrimental effects of increased SNS signaling is the premature graying of hair in response to stress. Secretion of NE resulting from stress causes differentiation of most hair pigment melanocyte stem cells (MeSCs) into melanocytes, rapidly depleting the hair follicle of pigment-producing cells as mature melanocytes undergo apoptosis and MeSCs are eventually eliminated. Blockade of NE SNS signaling preserves hair coloration in stressed animals. Increased SNS activation has serious apparently irreversible effects on homeostasis in both situations. Although neither report directly addresses aging, given that AD and the loss of hair pigmentation have strong age associations, it is of interest to better understand the role that SNS has in promoting age-associated phenotypes generally and determine if tuning the SNS through drug-mediated attenuation of SNS signaling may be of medical benefit.

Resting heart rate and the risk of cardiovascular disease, total cancer, and all-cause mortality - A systematic review and dose-response meta-analysis of prospective studies

BACKGROUND AND AIM

Epidemiological studies have reported increased risk of cardiovascular disease, cancer and all-cause mortality with greater resting heart rate, however, the evidence is not consistent. Differences by gender, adjustment for confounding factors, as well as the potential impact of subclinical disease are not clear. A previous meta-analysis missed a large number of studies, and data for atrial fibrillation have not been summarized before. We therefore aimed to clarify these associations in a systematic review and meta-analysis of prospective studies.

METHODS AND RESULTS

PubMed and Embase were searched up to 29 March 2017. Summary RRs and 95% confidence intervals (CIs) were calculated using random effects models. Eighty seven studies were included. The summary RR per 10 beats per minute increase in resting heart rate was 1.07 (95% CI: 1.05-1.10, I² = 61.9%, n = 31) for coronary heart disease, 1.09 (95% CI: 1.00-1.18, I² = 62.3%, n = 5) for sudden cardiac death, 1.18 (95% CI: 1.10-1.27, I² = 74.5%, n = 8) for heart failure, 0.97 (95% CI: 0.92-1.02, I² = 91.4%, n = 9) for atrial fibrillation, 1.06 (95% CI: 1.02-1.10, I² = 59.5%, n = 16) for total stroke, 1.15 (95% CI: 1.11-1.18, I² = 84.3%, n = 35) for cardiovascular disease, 1.14 (95% CI: 1.06-1.23, I² = 90.2%, n = 12) for total cancer, and 1.17 (95% CI: 1.14-1.19, I² = 94.0%, n = 48) for all-cause mortality. There was a positive dose-response relationship for all outcomes except for atrial fibrillation for which there was a J-shaped association.

CONCLUSION

This meta-analysis found an increased risk of coronary heart disease, sudden cardiac death, heart failure, atrial fibrillation, stroke, cardiovascular disease, total cancer and all-cause mortality with greater resting heart rate.

Volunteer Work, Religious Commitment, and Resting Pulse Rates

Research indicates that greater involvement in volunteer activities is associated with better health. We aim to contribute to this literature in two ways. First, rather than rely on self-reports of health, measured resting pulse rates serve as the dependent variable. Second, an effort is made to see if religious commitment moderates the relationship between volunteering and resting pulse rates. Data that come from a recent nationwide survey (N = 2265) suggest that volunteer work is associated with lower resting pulse rates. The results also reveal that the relationship between engaging in volunteer work and resting pulse rates improves among study participants who are more deeply committed to religion.

Trends in coronary risk factors and electrocardiogram findings from 1977 to 2009 with 10-year mortality in Japanese elderly males - The Tanushimaru Study

BACKGROUND

An understanding of the trends in regard to coronary risk factors and electrocardiogram (ECG) findings has an important role in public health. We investigated the trends in coronary risk factors and main ECG findings in 1977, 1989, 1999, and 2009 in the Japanese cohort of the Seven Countries Study, in Tanushimaru, a typical farming town on Kyushu Island.

METHODS AND RESULTS

A total of 1397 subjects (231 in 1977, 332 in 1989, 389 in 1999, and 445 in 2009) were enrolled in this study, and all of them were males aged over 65 years. In coronary risk factors, total cholesterol levels, diastolic blood pressure, body mass index, and uric acid significantly increased during these 3 decades. The prevalence of smokers markedly decreased from 56.7% in 1977 to 16.8% in 2009. ECG changes during 3 decades were wider QRS interval, increased prevalence of major abnormality, reduced heart rate, shortened PR interval and corrected QT, and decreased prevalence of left ventricular hypertrophy. Age, smoking habits, major and minor abnormalities in ECG were associated with mortality in 1977-1987. Age, total cholesterol levels (inversely) and corrected QT were associated with mortality in 1989-1999. Age, smoking habits, heart rate, and systolic blood pressure were associated with mortality in 1999-2009.

CONCLUSIONS

Predictors of mortality have changed with the times. Coronary risk factors such as smoking, increased heart rate, and elevated blood pressure have been recently associated with mortalities in elderly male Japanese general population.

An ecological approach to cognitive enhancement: complex motor training

Cognitive training has received a lot of attention recently, yielding findings that can be conflicting and controversial. In this paper, we present a novel approach to cognitive training based on complex motor activities. In a randomized controlled design, participants were assigned to one of three conditions: aerobic exercise, working memory training or designed sport--an intervention specifically tailored to include both physical and cognitive demands. After training for eight weeks, the designed sport group showed the largest gains in all cognitive measures, illustrating the efficacy of complex motor activities to enhance cognition. Designed sport training also revealed impressive health benefits, namely decreased heart rate and blood pressure. In this period of skepticism over the efficacy of computerized cognitive training, we discuss the potential of ecological interventions targeting both cognition and physical fitness, and propose some possible applications.

Assessment of potential cardiovascular risks of methylphenidate in comparison with sibutramine: do we need a SCOUT (trial)?

With the recent approval of methylphenidate (MPH) for treating attention-deficit/hyperactivity disorder (ADHD) in adults, the number of patients exposed will increase tremendously. The ongoing debate on the cardiovascular safety of MPH has triggered two large retrospective cohort studies in children and adolescents as well as in young to middle-aged adults. These studies looked into serious cardiovascular events (sudden cardiac death, acute myocardial infarction and stroke) as primary endpoints and concluded that MPH was safe after a mean duration of 2.1 years of follow-up in children and adolescents and mean duration of 0.33 years of current use in adults. The results are encouraging with respect to the short- and medium-term use of MPH. Without the inherent limitations of retrospective cohort studies, a prospective randomized, double-blind, placebo-controlled, multicenter trial in individuals stratified for cardiovascular risk factors would allow for an optimized risk assessment. With many millions of patients treated per year and drawing parallels to the lately discovered risks of sibutramine, another sympathomimetic with an overlapping mode of action and similar side effects on heart rate and blood pressure, we hypothesize that such a trial might be a dedicated risk mitigation strategy for public health. A critical assessment of cardiovascular side effects of MPH appears particularly warranted, because ADHD is associated with obesity, smoking and poor health in general. We summarize recent findings with the focus on cardiovascular risks of MPH in humans; we additionally analyze the limited number of rodent studies that have addressed cardiovascular risks of MPH.

Heart rate reduction and longevity in mice

Heart rate correlates inversely with life span across all species, including humans. In patients with cardiovascular disease, higher heart rate is associated with increased mortality, and such patients benefit from pharmacological heart rate reduction. However, cause-and-effect relationships between heart rate and longevity, notably in healthy individuals, are not established. We therefore prospectively studied the effects of a life-long pharmacological heart rate reduction on longevity in mice. We hypothesized, that the total number of cardiac cycles is constant, and that a 15% heart rate reduction might translate into a 15% increase in life span. C57BL6/J mice received either placebo or ivabradine at a dose of 50 mg/kg/day in drinking water from 12 weeks to death. Heart rate and body weight were monitored. Autopsy was performed on all non-autolytic cadavers, and parenchymal organs were evaluated macroscopically. Ivabradine reduced heart rate by 14% (median, interquartile range 12-15%) throughout life, and median life span was increased by 6.2% (p = 0.01). Body weight and macroscopic findings were not different between placebo and ivabradine. Life span was not increased to the same extent as heart rate was reduced, but nevertheless significantly prolonged by 6.2%.

Associations of Heart Rate With Inflammatory Markers Are Modulated by Gender and Obesity in Older Adults

BACKGROUND

Faster resting heart rate (HR), which is associated with inflammation and elevated cortisol levels, is a risk factor for excess cardiovascular morbidity and mortality. Obesity is associated with increased cardiovascular morbidity and mortality, inflammation, and elevated cortisol levels. The aim of the present study was to evaluate the interaction of Body Mass Index (BMI) with inflammation and cortisol in modulating HR in older subjects.

METHODS

We analyzed data of 895 participants aged 65+ enrolled in the "InCHIANTI" study, in sinus rhythm, and not taking beta blockers or digoxin. Linear regression was performed to assess the adjusted association between HR, IL-6, and cortisol levels. The model was also analyzed stratifying for BMI tertiles. Logistic regression was adopted for evaluating the association of HR exceeding the mean value with Il-6 and serum cortisol.

RESULTS

According to multivariable linear regression, IL-6 and cortisol levels were associated with HR (B = 1.42, 95% CI = 0.43-2.42; p = .005 and B = .34, 95% CI = 0.17-.51; p < .0001, respectively). The association was significant only among women in the highest BMI tertile (B = 4.16, 95% CI = 1.40-6.91; p = .003 for IL-6 and B = .57, 95% CI = 0.14-1.01; p = .010 for cortisol). Logistic regression confirmed that IL-6 and cortisol levels were associated with HR above the mean value in the highest BMI tertile (OR = 2.13, 95% CI = 1.15-3.97; p = .009 and OR = 1.14, 95% CI = 1.03-1.25; p = .009, respectively).

CONCLUSIONS

Faster HR is associated with proinflammatory state in elderly patients; this association seems to be limited to women with higher BMI.

Association between resting heart rate across the life course and all-cause mortality: longitudinal findings from the Medical Research Council (MRC) National Survey of Health and Development (NSHD)

BACKGROUND

Resting heart rate (RHR) is an independent risk factor for mortality. Nevertheless, it is unclear whether elevations in childhood and mid-adulthood RHR, including changes over time, are associated with mortality later in life. We sought to evaluate the association between RHR across the life course, along with its changes and all-cause mortality.

METHODS

We studied 4638 men and women from the Medical Research Council (MRC) National Survey of Health and Development (NSHD) cohort born during 1 week in 1946. RHR was obtained during childhood at ages 6, 7 and 11, and in mid-adulthood at ages 36 and 43. Using multivariable Cox regression, we calculated the HR for incident mortality according to RHR measured at each time point, along with changes in mid-adulthood RHR.

RESULTS

At age 11, those in the top fifth of the RHR distribution (≥97 bpm) had an increased adjusted hazard of 1.42 (95% CI 1.04 to 1.93) for all-cause mortality. A higher adjusted risk (HR, 95% CI 2.17, 1.40 to 3.36) of death was also observed for those in the highest fifth (≥81 bpm) at age 43. For a >25 bpm increased change in the RHR over the course of 7 years (age 36-43), the adjusted hazard was elevated more than threefold (HR, 95% CI 3.26, 1.54 to 6.90). After adjustment, RHR at ages 6, 7 and 36 were not associated with all-cause mortality.

CONCLUSIONS

Elevated RHR during childhood and midlife, along with greater changes in mid-adulthood RHR, are associated with an increased risk of all-cause mortality.