The Rancho Bernardo Study: 40 years studying why women have less heart disease than men and how diabetes modifies women's usual cardiac protection

Impact of Gender on Chronic Complications in Participants With Type 2 Diabetes: Evidence From a Cross-Sectional Study

INTRODUCTION

This study aimed to assess and compare the prevalence of diabetes complications between men and women with Type 2 diabetes (T2D), as well as how gender relates to these complications.

METHODS

In this cross-sectional study, complications of diabetes, including coronary artery disease (CAD), retinopathy, neuropathy and diabetic kidney disease (DKD), were evaluated in 1867 participants with T2D. Additionally, baseline characteristics of the individuals, including anthropometric measurements, metabolic parameters and the use of dyslipidaemia drugs and antihyperglycaemic agents, were assessed. Gender differences in complications were examined using the chi-squared test. Multivariate logistic regression was employed to investigate the relationship between gender and T2D complications, with and without adjusting for the characteristics of the studied population.

RESULTS

In the studied population, 62.1% had at least one complication, and complications were 33.5% for DKD, 29.6% for CAD, 22.9% for neuropathy and 19.1% for retinopathy. The prevalence of CAD and neuropathy was higher in men. However, DKD and retinopathy were more prevalent among women. Odds ratios of experiencing any complication, CAD and retinopathy in men compared with women were 1.57 (95% CI: 1.27-2.03), 2.27 (95% CI: 1.72-2.99) and 0.72 (95% CI: 0.52-0.98), respectively, after adjusting for demographic factors, anthropometric measures, metabolic parameters and the consumption of dyslipidaemia drugs and antihyperglycaemic agents.

CONCLUSION

The prevalence of diabetes complications was significantly higher in men with diabetes, highlighting the need for better treatment adherence. CAD was associated with the male gender, whereas retinopathy was associated with the female gender. Men and women with diabetes should be monitored closely for CAD and retinopathy, respectively, regardless of their age, diabetes duration, anthropometric measures, laboratory findings and medications.

Pulse pressure trajectories predict brain microstructure in community-dwelling older adults: Associations with executive function and modification by APOE

INTRODUCTION

Effects of chronic arterial stiffness on brain aging remain unclear. We, therefore, examined whether long-term trajectories of pulse pressure (PP) predicted brain microstructure, microstructure mediated PP-executive function associations, and APOE genotype modified PP-microstructure associations.

METHODS

We examined associations of PP trajectories with brain microstructure measured using restriction spectrum imaging in 146 community-dwelling older adults, whether microstructure mediated PP trajectory-executive function associations, and whether PP-restriction spectrum imaging correlations were modified by APOE-ε4 status.

RESULTS

Participants with trajectories of high PP had lower restricted isotropic diffusion (RI) compared to those with low PP trajectories and PP-executive function associations were mediated by subcortical and white matter RI. High PP more strongly correlated with lower RI and higher hindered diffusion among APOE-ε4 carriers than non-carriers.

DISCUSSION

Prolonged elevated PP predicts microstructural abnormalities which may contribute to impaired executive function. APOE-ε4 carriers may be most vulnerable to the adverse effects of PP on brain microstructure.

Association between osteoarthritis and urinary tract infection in older adults: A nationwide population-based cohort study

Osteoarthritis (OA) may increase urinary tract infection (UTI) in older adults. However, this issue remains unclear. We identified 8599 older patients (≥65 years) with OA, and an equal number of older patients without OA, matched by age, sex, and index date from the Taiwan National Health Insurance Research Database between 2001 and 2005. Past histories, including UTI and underlying comorbidities, were included in the analyses. Comparisons for any UTI, ≥1 hospitalization for UTI, and ≥3 hospitalizations for UTI between the 2 cohorts by following up until 2015 were performed. In both cohorts, the percentages of age subgroups were 65-74 years (65.7%), 75-84 years (30.1%), and ≥85 years (4.2%). The male sex was 42.4%. Patients with OA had an increased risk of any UTI compared with those without OA after adjusting for all past histories (adjusted hazard ratio [AHR]: 1.72; 95% confidence interval [CI]: 1.64-1.80). Compared with patients without OA, patients with OA also had an increased risk of ≥1 hospitalization for UTI and ≥3 hospitalizations for UTI (AHR: 1.13; 95% CI: 1.06-1.19 and AHR: 1.25; 95% CI: 1.13-1.38, respectively). In addition to OA, age 75-84 years, female sex, history of UTI, benign prostatic hyperplasia, indwelling urinary catheter, cerebrovascular disease, dementia, and urolithiasis were independent predictors for any UTI. This study showed that OA was associated with UTI in older adults. We suggest appropriately managing OA and controlling underlying comorbidities to prevent subsequent UTI.

Dual impairments in visual and hearing acuity and age-related cognitive decline in older adults from the Rancho Bernardo Study of Healthy Aging

BACKGROUND

We examined the associations between dual impairments in visual and hearing acuity and aging-related cognitive decline.

METHODS

This was a longitudinal study of adults who had visual and hearing acuity and cognitive function assessed in 1992-1996 and were followed for up to 24 years (mean = 7.3 years), with up to five additional cognitive assessments. Visual impairment was defined as vision worse than 20/40, hearing impairment as pure-tone average thresholds >25 dB. Associations were tested using linear mixed-effects regressions.

RESULTS

Of 1,383 participants, 293 had visual impairment, 990 had a hearing impairment and 251 had both deficits. In fully adjusted models, low visual acuity was associated with poorer Mini-Mental State Examination (MMSE; β = -0.29) and Trail-Making Test Part B (Trails B; β = 13.22) performance, and with faster declines in MMSE (β = -0.12) and Trails B (β = 1.84). The combination of low visual and low hearing acuity was associated with poorer MMSE (β = -0.44) and Trails B (β = 11.20) scores, and with faster declines in MMSE (β = -0.19), Trails B (β = 3.50), and Verbal Fluency Test (VFT; β = -0.14) performance. Associations were similar in men and women.

CONCLUSION

Impairments in both vision and hearing are associated with a more rapid decline in cognitive function with aging.

Age and Sex Differences in the Associations of Pulse Pressure With White Matter and Subcortical Microstructure

Midlife vascular disease increases risk for dementia and effects of vascular dysfunction on brain health differ between men and women. Elevated pulse pressure, a surrogate for arterial stiffness, contributes to cerebrovascular pathology and white matter damage that may advance cognitive aging; however, it remains unclear how associations between pulse pressure and neural integrity differ by sex and age. This study used restriction spectrum imaging to examine associations between pulse pressure and brain microstructure in community-dwelling women (N=88) and men (N=55), aged 56 to 97 (mean, 76.3) years. Restricted isotropic (presumed intracellular), hindered isotropic (presumed extracellular), neurite density, and free water diffusion were computed in white matter tracts and subcortical regions. After adjustment for age and sex, higher pulse pressure correlated with lower restricted isotropic diffusion in global white matter, with more pronounced associations in parahippocampal cingulum, as well as in thalamus and hippocampus. Subgroup analyses demonstrated stronger correlations between pulse pressure and restricted isotropic diffusion in association fibers for participants ≤75 years than for older participants, with stronger effects for women than men of this age group. Microstructure in parahippocampal cingulum and thalamus differed by pulse pressure level regardless of antihypertensive treatment. Increased pulse pressure may lead to widespread injury to white matter and subcortical structures, with greatest vulnerability for women in late middle to early older age. Restriction spectrum imaging could be useful for monitoring microstructural changes indicative of neuronal loss or shrinkage, demyelination, or inflammation that accompany age-related cerebrovascular dysfunction.

Physical Activity and Trajectories of Cognitive Change in Community-Dwelling Older Adults: The Rancho Bernardo Study

BACKGROUND

Although physical activity has been associated with better cognitive function and reduced dementia risk, its association with cognitive decline in normal aging remains uncertain.

OBJECTIVE

To determine whether physical activity in youth and older age are associated with age-related cognitive change.

METHODS

Over a period of 27 years, 2,027 community-dwelling adults (mean age 73.5; 60% women) of the Rancho Bernardo Study of Healthy Aging completed up to seven cognitive assessments, including tests of global cognitive function, executive function, verbal fluency, and episodic memory. At each visit, participants reported concurrent physical activity. At baseline (1988- 1992), participants additionally reported physical activity as a teenager and at age 30. For each age period, participants were classified as regularly active (3+ times/week) or inactive.

RESULTS

Associations between concurrent physical activity and better cognitive function were stronger with advancing age on all tests, even after accounting for education, health, and lifestyle factors, as well as survival differences (ps < 0.05). Baseline physical activity did not predict rates of cognitive decline (ps > 0.40). Individuals who were physically active at age 30 and older age maintained the highest global cognitive function with advancing age (p = 0.002).

CONCLUSION

Regular physical activity is associated with better cognitive function with advancing age. Physical activity in young adulthood may contribute to cognitive reserve, which together with physical activity in later years, may act to preserve cognitive function with age.

Hypertension and Age-Related Cognitive Impairment: Common Risk Factors and a Role for Precision Aging

Purpose of Review

Precision Aging® is a novel concept that we have recently employed to describe how the model of precision medicine can be used to understand and define the multivariate risks that drive age-related cognitive impairment (ARCI). Hypertension and cardiovascular disease are key risk factors for both brain function and cognitive aging. In this review, we will discuss the common mechanisms underlying the risk factors for both hypertension and ARCI and how the convergence of these mechanisms may be amplified in an individual to drive changes in brain health and accelerate cognitive decline.

Recent Findings

Currently, our cognitive health span does not match our life span. Age-related cognitive impairment and preventing and treating ARCI will require an in-depth understanding of the interrelated risk factors, including individual genetic profiles, that affect brain health and brain aging. Hypertension and cardiovascular disease are important risk factors for ARCI. And, many of the risk factors for developing hypertension, such as diabetes, smoking, stress, viral infection, and age, are shared with the development of ARCI. We must first understand the mechanisms common to the converging risk factors in hypertension and ARCI and then design person-specific therapies to optimize individual brain health.

Summary

The understanding of the convergence of shared risk factors between hypertension and ARCI is required to develop individualized interventions to optimize brain health across the life span. We will conclude with a discussion of possible steps that may be taken to decrease ARCI and optimize an individual’s cognitive life span.

Associations between age and brain microstructure in older community-dwelling men and women: the Rancho Bernardo Study

Cytoarchitectural brain changes during normal aging remain poorly characterized, and it is unclear whether patterns of brain aging differ by sex. This study used restriction spectrum imaging to examine associations between age and brain microstructure in 147 community-dwelling participants (aged 56-99 years). Widespread associations with age in multiple diffusion compartments, including increased free water, decreased restricted and hindered diffusion, and reduced neurite complexity, were observed in the cortical gray matter, the white matter tracts, and the hippocampus. Age differences in cortical microstructure were largely independent of atrophy. Associations were mostly global, although foci of stronger effects emerged in the fornix, anterior thalamic radiation and commissural fibers, and the medial temporal, orbitofrontal, and occipital cortices. Age differences were stronger and more widespread for women than men, even after adjustment for education, hypertension, and body mass index. Restriction spectrum imaging may be a convenient, noninvasive tool for monitoring changes in diffusion properties that are thought to reflect reduced cellular fractions and neurite density or complexity, which occur with typical aging, and for detecting sex differences in patterns of brain aging.

Sex difference in the incidence of microvascular complications in patients with type 2 diabetes mellitus: a prospective cohort study

AIMS

Type 2 diabetes mellitus is a major cause of death and disability due to its long-term macro- and microvascular diseases. Although women with type 2 diabetes have more macrovascular diseases, it is unclear whether there are sex differences in the occurrence of microvascular disease. The aim of our study was to investigate sex differences in the incidence of microvascular complications in type 2 diabetes.

METHODS

Analyses were performed in the DiaGene study, a prospective cohort study for complications of type 2 diabetes, collected in the city of Eindhoven, the Netherlands (n = 1886, mean follow-up time = 6.93 years). Cox proportional hazard models adjusted for risk factors for complications (age, smoking, hypertension, dyslipidemia, HbA1c and duration of type 2 diabetes) were used to analyze the incidence of microvascular complications in men and women.

RESULTS

The incidence of microalbuminuria was significantly higher in men (HR microalbuminuria 1.64 [CI 1.21-2.24], p = 0.002). Additionally, men are more likely to develop two or three microvascular complications compared to women (OR 2.42 [CI 1.69-3.45], p < 0.001).

CONCLUSIONS

This study shows that men with type 2 diabetes are more likely to develop microvascular complications, especially microalbuminuria. Furthermore, men seem to have a higher chance of developing multiple microvascular complications. Our results highlight that men and women may not benefit to a similar extent from current treatment approaches to prevent diabetes-related microvascular diseases.

Cardiovascular Disease in Women Across the Lifespan: The Importance of Sleep

Cardiovascular disease (CVD) and sleep disturbances are both common and associated with significant morbidity and mortality. Compared with men, women are more likely to report insufficient sleep. During the 2018 Research Conference on Sleep and the Health of Women sponsored by the National Heart, Lung, and Blood Institute, researchers in cardiology, integrative physiology and sleep medicine reviewed the current understanding of how sleep and sleep disturbances influence CVD in women across the lifespan. Women may be particularly vulnerable to the negative effects of sleep disturbances at important stages of their life, including during pregnancy and after menopause. The proposed pathways linking sleep disturbances and adverse cardiovascular outcomes in women are numerous and the complex interaction between them is not well understood. Future research focused on understanding the scope of sleep disorders in women, defining the underlying mechanisms, and testing interventions to improve sleep are critical for improving the cardiovascular health of all women.

Risk of acute mesenteric ischemia in patients with diabetes: A population-based cohort study in Taiwan

BACKGROUND AND AIMS

Diabetes is a common and complex endocrine disorder that often results in hyperglycemia, which has been strongly implicated in several cardiovascular and cerebrovascular events that cause disability. Acute mesenteric ischemia (AMI) is a vascular emergency with high mortality rates. We conducted a population-based cohort study that utilizes data from medical claims databases to investigate whether diabetes increases the risk of AMI.

METHODS

Using claims data from Taiwan's National Health Insurance program, 66,624 diabetic patients were enrolled from 1998 to 2009, and a comparison group of 266,496 individually matched subjects without diabetes was selected. The two groups were followed up until diagnosis of AMI, death, or the end of 2011. Incidence rates of AMI were assessed in both groups. Cox proportional hazards models were used to estimate the hazard ratios of diabetes for AMI.

RESULTS

The diabetes cohort had a higher incidence rate than the comparison cohort for AMI (0.56 vs. 0.29 per 1,000 person-years). After adjusting for sex, age, comorbidity, and health system utilization, the adjusted hazard ratio of diabetes was 1.32 (95% confidence interval 1.11-1.56) for AMI. The risk of AMI associated with diabetes was greater in men (adjusted hazard ratio = 1.48, 95% confidence interval 1.17-1.87) than in women (adjusted hazard ratio = 1.17, 95% confidence interval 0.92-1.49).

CONCLUSIONS

There was an increased risk of AMI in patients with diabetes. However, further research is required to understand whether this association is causal or due to a common set of risk factors.

Use of Spontaneous Reporting Systems to Detect Host-Medication Interactions: Sex Differences in Oral Anti-Diabetic Drug-Associated Myocardial Infarction

Background Medical treatment should be tailored to an individual's characteristics to optimize treatment benefits. We examined whether case-only analyses from spontaneous reporting systems can detect host-medication interactions in oral antidiabetic drug-associated myocardial infarction. Methods and Results Interaction between sex and use of oral antidiabetic drugs was mined among patients with myocardial infarction in the US Food and Drug Administration Adverse Event Reporting System from 2004 to 2014, including 55 718 males and 42 428 females. The odds ratio ( OR ) of multiplicative interactions was used to estimate sex-drug interaction. Detected signs of these interactions were then validated by a nested case-control study utilizing a healthcare record database, Taiwan's National Health Insurance Research Database, from 2001 to 2014, including 31 585 cases and 126 340 controls. In the US Food and Drug Administration Adverse Event Reporting System, a higher proportion of male than female patients used metformin (10.32% in males versus 7.82% in females) and sulfonylureas (4.75% in males versus 3.43% in females); after adjusting for patients' pharmacy-based chronic disease score, males had a higher risk of metformin-associated ( OR =1.07; 99% confidence interval, 1.00-1.14) and sulfonylureas-associated ( OR =1.21; 99% confidence interval, 1.10-1.33) myocardial infarction than females. Detected signs of sex-drug interactions were validated in the National Health Insurance Research Database ( OR for metformin=1.14; 99% confidence interval, 1.03-1.26; OR for sulfonylureas=1.13; 99% confidence interval, 1.02-1.25). Conclusions Males have a higher risk of metformin- and sulfonylureas-associated myocardial infarction than females, which suggests that sex-drug interactions are a key issue in diabetes mellitus treatment plan development. This case-only approach using information from spontaneous reporting systems may be a potential tool for screening host-medication interactions that cause adverse events.

Sex differences in the association between diabetes and risk of cardiovascular disease, cancer, and all-cause and cause-specific mortality: a systematic review and meta-analysis of 5,162,654 participants

BACKGROUND

Studies have suggested sex differences in the mortality rate associated with diabetes. We conducted a meta-analysis to estimate the relative effect of diabetes on the risk of all-cause, cancer, cardiovascular disease (CVD), infectious disease, and respiratory disease mortality in women compared with men.

METHODS

Studies published from their inception to April 1, 2018, identified through a systematic search of PubMed and EMBASE and review of references. We used the sex-specific RRs to derive the women-to-men ratio of RRs (RRR) and 95% CIs from each study. Subsequently, the RRR for each outcome was pooled with random-effects meta-analysis weighted by the inverse of the variances of the log RRRs.

RESULTS

Forty-nine studies with 86 prospective cohorts met the inclusion criteria and were eligible for analysis. The pooled women-to-men RRR showed a 13% greater risk of all-cause mortality associated with diabetes in women than in men (RRR 1.13, 95% CI 1.07 to 1.19; P < 0.001). The pooled multiple-adjusted RRR indicated a 30% significantly greater excess risk of CVD mortality in women with diabetes compared with men (RRR 1.30, 95% CI 1.13 to 1.49; P < 0.001). Compared with men with diabetes, women with diabetes had a 58% greater risk of coronary heart disease (CHD) mortality, but only an 8% greater risk of stroke mortality (RRR_CHD 1.58, 95% CI 1.32 to 1.90; P < 0.001; RRR_stroke 1.08, 95% CI 1.01 to 1.15; P < 0.001). However, no sex differences were observed in pooled results of populations with or without diabetes for all-cancer (RRR 1.02, 95% CI 0.98 to 1.06; P = 0.21), infectious (RRR 1.13, 95% CI 0.90 to 1.38; P = 0.33), and respiratory mortality (RRR 1.08, 95% CI 0.95 to 1.23; P = 0.26).

CONCLUSIONS

Compared with men with the same condition, women with diabetes have a 58% and 13% greater risk of CHD and all-cause mortality, respectively, although there was a significant heterogeneity between studies. This points to an urgent need to develop sex- and gender-specific risk assessment strategies and therapeutic interventions that target diabetes management in the context of CHD prevention.

Risk of all-cause and CHD mortality in women versus men with type 2 diabetes: a systematic review and meta-analysis

OBJECTIVE

Previous studies have shown sex-specific differences in all-cause and CHD mortality in type 2 diabetes. We performed a systematic review and meta-analysis to provide a global picture of the estimated influence of type 2 diabetes on the risk of all-cause and CHD mortality in women vs men.

METHODS

We systematically searched PubMed, EMBASE and Web of Science for studies published from their starting dates to Aug 7, 2018. The sex-specific hazard ratios (HRs) and their pooled ratio (women vs men) of all-cause and CHD mortality associated with type 2 diabetes were obtained through an inverse variance-weighted random-effects meta-analysis. Subgroup analyses were used to explore the potential sources of heterogeneity.

RESULTS

The 35 analyzed prospective cohort studies included 2 314 292 individuals, among whom 254 038 all-cause deaths occurred. The pooled women vs men ratio of the HRs for all-cause and CHD mortality were 1.17 (95% CI: 1.12-1.23, I2 = 81.6%) and 1.97 (95% CI: 1.49-2.61, I2 = 86.4%), respectively. The pooled estimate of the HR for all-cause mortality was approximately 1.30 in articles in which the duration of follow-up was longer than 10 years and 1.10 in articles in which the duration of follow-up was less than 10 years. The pooled HRs for all-cause mortality in patients with type 2 diabetes was 2.33 (95% CI: 2.02-2.69) in women and 1.91 (95% CI: 1.72-2.12) in men, compared with their healthy counterparts.

CONCLUSIONS

The effect of diabetes on all-cause and CHD mortality is approximately 17 and 97% greater, respectively, for women than for men.

Weight cycling and cardiovascular outcome in women with suspected ischemia: A report from the NHLBI-sponsored WISE Study

BACKGROUND

We previously reported in a cross-sectional analysis an adverse relationship between weight cycling and HDL-cholesterol but not angiographic obstructive coronary artery disease (CAD) among women undergoing coronary angiography for suspected ischemia in the NHLBI-sponsored Women's Ischemia Syndrome Evaluation (WISE). We now examine the relationship between weight cycling and prospective adverse cardiovascular outcome in this group.

METHODS

795 women enrolled between 1996-2001 in the WISE undergoing coronary angiography for evaluation of suspected ischemia and followed for a median of 6.0 years (interquartile range = 3.4 years). Adverse outcome was defined as a composite of all-cause death, cardiovascular mortality, non-fatal myocardial infarction, non-fatal stroke, and hospitalization for heart failure. Weight cycling was defined as the intentional loss of at least 10 lbs. (4.5 kgs.) at least three times during the women's lifetime.

RESULTS

Women (n = 224) who reported a history of weight cycling were younger; more often white and better educated compared those without this history. At baseline, women with a weight cycling history had lower HDL-C values, higher body mass index, larger waist circumferences and higher values for fasting blood sugar, but no difference in obstructive CAD prevalence or severity. There was an inverse relationship between weight cycling and adverse composite cardiovascular outcome, whereby fewer of women with a history of weight cycling experienced an adverse outcome as compared to non-cyclers (21% vs 29%, respectively, p = 0.03).

CONCLUSIONS

Despite an adverse association with HDL-cholesterol in women undergoing coronary angiography for suspected ischemia, weight cycling was associated with a lower adverse outcome rate in women with suspected ischemia.

Endocrine treatment of aging transgender people

High quality empirical data assessing morbidity and mortality and cancer incidence among transgender people are almost non-existent. Sex hormone treatment of conditions in older non-transgender people might as yet be taken as the best available analogy to hormone administration to aging transgender persons. Testosterone administration to transgender men carries little risk with regard to cardiovascular disease and cancer. A dose adaptation may be needed in men with a high hematocrit or cardiac insufficiency. In transgender men, even after breast ablation, breast cancer may occur in residual mammary tissue. Treatment with estrogens (specifically oral ethinylestradiol) of transgender women, particularly in combination with progestins, carries a significant relative risk of developing cardiovascular disease (almost a twofold incidence compared to the general population). The dose of estrogens may have to be reduced with aging. A change from oral to probably safer transdermal estrogens must be considered. Though rare, tumors of the breasts, prostate, meninges and pituitary have been encountered. Based upon the available expertise, initiation of cross-sex hormone treatment in elderly subjects is without disproportionate risks.

Nonfasting Glucose and Incident Stroke and Its Types - The Circulatory Risk in Communities Study (CIRCS)

BACKGROUND

The effect of postprandial glucose on the risk of cardiovascular disease has been emphasized, but it is controversial whether nonfasting glucose is related to incident stroke and its types.

METHODS AND RESULTS

We investigated the associations of nonfasting glucose with incident stroke and its types among 7,198 participants aged 40-74 years from the Circulatory Risk in Communities Study, enrolled in 1995-2000. We estimated multivariable hazard ratios (HR) using Cox proportional hazard models. Over a median follow-up of 14.1 years, 291 cases of total stroke (ischemic strokes: 191 including 109 lacunar infarctions) were identified. Nonfasting glucose concentration was associated with greater risk of incident total stroke, ischemic stroke and lacunar infarction when modeled categorically (for prediabetic type: 7.8-11.0 mmol/L vs. normal type: <7.8 mmol/L among all subjects, HR for lacunar infarction was 2.02, 95% confidence interval (CI): 1.19, 3.43) or continuously (per one standard deviation increment among all subjects, HR for lacunar infarction was 1.29, 95% CI: 1.15, 1.45). Diabetic type showed similar results. Population attributable fractions of nonfasting hyperglycemia were 13.2% for ischemic stroke and 17.4% for lacunar infarction.

CONCLUSIONS

Nonfasting glucose concentration, either as a diagnosis of prediabetic and diabetic types or as a continuous variable, proved to be an independent predictor significantly attributed to incident total stroke, especially ischemic stroke and lacunar infarction, in the general population.

Aging and sex hormones in males

Several large cohort studies have disclosed the trajectories of sex steroids changes overtime in men and their clinical significance. In men the slow, physiological decline of serum testosterone (T) with advancing age overlaps with the clinical condition of overt, pathological hypogonadism. In addition, the increasing number of comorbidities, together with the high prevalence of chronic diseases, all further contribute to the decrease of serum T concentrations in the aging male. For all these reasons both the diagnosis of late-onset hypogonadism (LOH) in men and the decision about starting or not T replacement treatment remain challenging. At present, the biochemical finding of T deficiency alone is not sufficient for diagnosing hypogonadism in older men. Coupling hypogonadal symptoms with documented low serum T represents the best strategy to refine the diagnosis of hypogonadism in older men and to avoid unnecessary treatments.

Sex differences in micro- and macro-vascular complications of diabetes mellitus

Vascular complications are a leading cause of morbidity and mortality in both men and women with type 1 (T1DM) or type 2 (T2DM) diabetes mellitus, however the prevalence, progression and pathophysiology of both microvascular (nephropathy, neuropathy and retinopathy) and macrovascular [coronary heart disease (CHD), myocardial infarction, peripheral arterial disease (PAD) and stroke] disease are different in the two sexes. In general, men appear to be at a higher risk for diabetic microvascular complications, while the consequences of macrovascular complications may be greater in women. Interestingly, in the absence of diabetes, women have a far lower risk of either micro- or macro-vascular disease compared with men for much of their lifespan. Thus, the presence of diabetes confers greater risk for vascular complications in women compared with men and some of the potential reasons, including contribution of sex hormones and sex-specific risk factors are discussed in this review. There is a growing body of evidence that sex hormones play an important role in the regulation of cardiovascular function. While estrogens are generally considered to be cardioprotective and androgens detrimental to cardiovascular health, recent findings challenge these assumptions and demonstrate diversity and complexity of sex hormone action on target tissues, especially in the setting of diabetes. While some progress has been made toward understanding the underlying mechanisms of sex differences in the pathophysiology of diabetic vascular complications, many questions and controversies remain. Future research leading to understanding of these mechanisms may contribute to personalized- and sex-specific treatment for diabetic micro- and macro-vascular disease.

Time-restricted feeding improves insulin resistance and hepatic steatosis in a mouse model of postmenopausal obesity

BACKGROUND

Menopause is associated with significant hormonal changes that result in increased total body fat and abdominal fat, amplifying the risk for metabolic syndrome and diseases such as diabetes, cardiovascular disease and cancer in postmenopausal women. Intermittent fasting regimens hold significant health benefit promise for obese humans, however, regimens that include extreme daytime calorie restriction or daytime fasting are generally associated with hunger and irritability, hampering long-term compliance and adoption in the clinical setting. Time-restricted feeding (TRF), a regimen allowing eating only during a specific period in the normal circadian feeding cycle, without calorie restriction, may increase compliance and provide a more clinically viable method for reducing the detrimental metabolic consequences associated with obesity.

METHODS

We tested TRF as an intervention in a mouse model of postmenopausal obesity. Metabolic parameters were measured using Clinical Laboratory Animal Monitoring System (CLAMS) and we carried out glucose tolerance tests. We also stained liver sections with oil red O to examine steatosis and measured gene expression related to gluconeogenesis.

RESULTS

Preexisting metabolic disease was significantly attenuated during 7 weeks of TRF. Despite having access to the same high fat diet (HFD) as ad libitum fed (ALF) mice, TRF mice experienced rapid weight loss followed by a delayed improvement in insulin resistance and a reduced severity of hepatic steatosis by having access to the HFD for only 8h during their normal nocturnal feeding period. The lower respiratory exchange ratio in the TRF group compared with the ALF group early in the dark phase suggested that fat was the predominant fuel source in the TRF group and correlated with gene expression analyses that suggested a switch from gluconeogenesis to ketogenesis. In addition, TRF mice were more physically active than ALF fed mice.

CONCLUSIONS

Our data support further analysis of TRF as a clinically viable form of intermittent fasting to improve metabolic health due to obesity.

Autoimmune diabetes in adults and risk of myocardial infarction: the HUNT study in Norway

BACKGROUND

The long-term consequences of autoimmune diabetes in adults (AIDA) are largely unexplored.

OBJECTIVE

To investigate the risk of myocardial infarction (MI) in AIDA compared to type 2 diabetes, taking into consideration the effects of socio-economic and lifestyle factors, the metabolic syndrome and glycaemic control.

METHODS

A total of 62 995 participants including 207 individuals with AIDA (onset ≥35 years and anti-GAD positive) and 2322 individuals with type 2 diabetes (onset ≥35 years and anti-GAD negative), from the population-based Norwegian HUNT study, were followed for a first MI during the period 1995-2008. We identified 2614 MIs by hospital records or the National Cause of Death Registry. Cox proportional hazard models were used to estimate the risk of MI by diabetes subgroups after adjustment for age and socio-economic and lifestyle factors.

RESULTS

AIDA amongst women was associated with a nearly fourfold increased risk of MI [hazard ratio (HR) 3.63, 95% confidence interval (CI) 2.21-5.96) compared to nondiabetic participants, whereas no excess risk was found in men with AIDA (HR 1.30, 95% CI 0.70-2.52). By contrast, type 2 diabetes was associated with an increased MI risk in both men (HR 1.92, 95% CI 1.62-2.26) and women (HR 2.39, 95% CI 1.98-2.89). The metabolic profile was more favourable in patients with AIDA than in those with type 2 diabetes, but glycaemic control was worse. Multivariable models and sensitivity analyses suggest that these results were robust.

CONCLUSIONS

Women with AIDA were more likely to develop MI, compared to men with AIDA and both men and women with type 2 diabetes. Further investigations are warranted to confirm this gender difference.

Sex-specific differential in risk of diabetes-related macrovascular outcomes

Reports from recent studies suggest that diabetes confers a higher risk of cardiovascular disease in women compared to men. Larger studies, including meta-analyses, report that women with diabetes have a 44 % greater risk of incident coronary heart disease and a 27 % greater risk of incident stroke compared to men with diabetes. In this article, we summarize results from longitudinal studies that examine sex differences in risk factors for and rates of macrovascular complications from diabetes. We also discuss possible mechanisms for increased cardiovascular risk associated with diabetes in women compared to men, including the clustering of hypertension, obesity, and elevated triglycerides, the possible contribution of hormonal differences, and sex differences in the prescription of and adherence to pharmacologic treatment. In conclusion, diabetes is associated with a slightly higher risk of cardiovascular disease in women compared to men. Future studies should further explore the reasons underlying imperfect use of medications that lower cardiovascular risk in both women and men with diabetes.

Endogenous Sex Steroid Hormones, Lipid Subfractions, and Ectopic Adiposity in Asian Indians

BACKGROUND

Estradiol, testosterone (T), and sex hormone binding globulin (SHBG) levels are associated with lipid subfractions in men and women. Our objective was to determine if associations are independent from adipose tissue area among Asian Indians.

METHODS

We used data from 42 women and 57 Asian Indian men who did not use exogenous steroids or lipid-lowering medications. Lipoprotein subfractions including low-density lipoprotein cholesterol (LDL), very low-density lipoprotein cholesterol (VLDL), and intermediate density lipoprotein (IDL) were assessed by ion mobility spectrometry. Intra-abdominal adiposity was assessed by computed tomography. Multivariable regression models estimated the association between sex hormones with lipoprotein subfractions before and after adjustment for adiposity.

RESULTS

Among women, lower logSHBG levels were associated with smaller logLDL particle size and higher logtriglycerides, logVLDL, and logIDL, although these associations were attenuated with adjustment for visceral adiposity in particular. Among women, lower logSHBG levels was significantly associated with lower logmedium LDL and logsmall LDL concentrations even after consideration of visceral and hepatic adiposity and insulin resistance as represented by the homeostasis model assessment of insulin resistance (HOMA-IR). Among men, lower logSHBG was also associated with smaller logLDL peak diameter size and higher logtriglycerides and logVLDL, even after adjustment for HOMA-IR and adiposity. Relationships between sex steroids and lipid subfractions were not significant among women. Among men, higher total testosterone was associated with higher logHDL and logLDL particle size, and lower logtriglycerides and logVLDL, but these associations were partially attenuated with adjustment for adiposity and HOMA-IR.

CONCLUSIONS

Among Asian Indians, SHBG is associated with more favorable lipid subfraction concentrations, independent of hepatic and visceral fat.

The Effects of Fetal Gender on Maternal and Fetal Insulin Resistance

OBJECTIVE

Gender plays a role in the development of a number of cardiovascular and metabolic diseases and it has been suggested that females may be more insulin resistant in utero. We sought to assess the relationship between infant gender and insulin resistance in a large pregnancy cohort.

STUDY DESIGN

This is a secondary analysis of a cohort from the ROLO randomized control trial of low GI diet in pregnancy. Serum insulin, glucose and leptin were measured in early pregnancy and at 28 weeks. At delivery cord blood C-peptide and leptin were measured. A comparison of maternal factors, fetal biometry, insulin resistance and leptin was made between male and female offspring. A multivariate regression model was built to account for the possible effects of maternal BMI, birthweight and original study group assignment on findings.

RESULTS

A total of 582 women were included in this secondary analysis, of whom 304 (52.2%) gave birth to male and 278 (47.8%) gave birth to female infants. Compared to male infants at birth, female infants were significantly lighter, (3945 ± 436 vs. 4081± 549g, p<0.001), shorter in length (52.36 ± 2.3 vs. 53.05 ± 2.4cm, p<0.001) and with smaller head circumferences (35.36 ± 1.5 vs. 36.10 ± 1.1cm, p<0.001) than males. On multiple regression analysis, women pregnant with female fetuses were less insulin resistant in early pregnancy, i.e. had lower HOMA indices (B = -0.19, p = 0.01). Additionally female fetuses had higher concentrations of both cord blood leptin and C-peptide at birth when compared to male offspring (B = 0.38, p<0.001 and B = 0.31, p = 0.03 respectively).

CONCLUSION

These findings suggest gender is a risk factor for insulin resistance in-utero. Additionally, carrying a female fetus decreases the risk of insulin resistance in the mother, from as early as the first trimester.

A review of the relationships between endogenous sex steroids and incident ischemic stroke and coronary heart disease events

For decades, it has been recognized that men have a higher age-adjusted risk of ischemic cardiovascular (CVD) events compared to women, thus generating hypotheses that sex steroids contribute to CVD risk. Potential mechanisms include genomic and non-genomic effects of sex steroids as well as mediation through classic CVD risk factors and obesity. However, results from randomized studies suggest that sex steroid supplementation in men and women do not result in improved CVD outcomes and may increase CVD risk. In contrast, prospective observations from endogenous sex steroid studies, i.e. among participants not using sex steroids, have suggested the opposite relationship. We reviewed the findings of prospective observational studies in men (17 studies) and women (8 studies) that examined endogenous sex steroids and CVD risk. These studies suggested a lack of association or that lower levels of testosterone or dihydrotestosterone are associated with higher CVD risk in both men and women. Higher, rather than lower, estradiol levels were associated with higher CVD risk in women. There were several significant gaps in the literature. First, it is unclear whether more sensitive measures of sex steroid levels might detect significant differences. Second, there are few prospective studies in women. Similarly, no studies report outcomes for high-risk groups such as African-Americans and Hispanics. Finally, few studies report upon ischemic coronary disease as opposed to ischemic stroke separately, although relationships between sex steroids and CVD may vary by vascular bed. Future investigations need to examine high risk groups and to distinguish between subtypes of CVD.

Risk of Incident Coronary Heart Disease Events in Men Compared to Women by Menopause Type and Race

Background

We examined whether type of menopause affects sex differences in coronary heart disease (CHD) events and whether the impact is similar in blacks and whites.

Methods and Results

Participants were enrolled in the Reasons for Geographic and Racial Differences in Stroke (REGARDS) cohort between 2003 and 2007 without CHD at baseline (n=23 086). Cox regression models were used to calculate the hazard of incident nonfatal CHD (definite or probable myocardial infarction) and acute CHD death, adjusting for age, age at last menstrual period <45 years, region, education level, income, diabetes, smoking, systolic blood pressure, lipid levels, albumin-creatinine ratio, physical activity, C-reactive protein, body mass index, waist circumference, and medication use. White women in natural menopause (hazard ratio [HR], 0.45; 95% confidence interval [CI], 0.31, 0.66) and surgical menopause (HR, 0.65; 95% CI, 0.42, 0.99) had a reduced hazard of nonfatal events, compared to white men. Black women in natural menopause (HR, 0.69; 95% CI, 0.47, 1.03), but not surgical menopause (HR, 0.81; 95% CI, 0.51, 1.29), had a marginally reduced hazard of nonfatal events, compared to black men. Women had lower risk of acute CHD death than men regardless of their menopause type and race.

Conclusions

Sex differences in the risk of incident CHD events were larger among whites than blacks and varied by type of menopause. Women consistently had a lower risk of incident CHD death than men, but the magnitude of sex differences was greater in whites than blacks for nonfatal events, regardless of menopause type.

Reducing women's cardiovascular disease risk profile

Heart disease is the leading cause of death in women. Unique risk factors have been recognized, including pre-eclampsia, eclampsia and autoimmune diseases. Diabetes and hypertension (HTN) also play a unique role in women. Women with diabetes have a higher risk for coronary heart disease and microvascular disease compared with males. Additionally, older women have a high prevalence of uncontrolled HTN and women tend to have more treatment resistant HTN, increasing risk for cardiovascular events and mortality. The outcomes of cardiovascular disease have shown an increase in the number of heart attacks in younger women, though there is decreasing mortality. Treatment with coronary artery bypass graft surgery and percutaneous intervention has also shown to have poorer outcomes in women.

Sex differences in the association of fasting and postchallenge glucose levels with grip strength among older adults: the Rancho Bernardo Study

OBJECTIVE

Persons with diabetes have accelerated muscle loss. The association of fasting and postchallenge glucose levels per se to grip strength, a clinical marker of poor physical function, and potential sex differences in this relationship has not been previously described.

DESIGN

Longitudinal cohort.

SETTING

USA.

PARTICIPANTS

Participants were community-dwelling older adults (mean age 71.3 years) without self-reported diabetes and/or use of diabetes medication with glucose measured at baseline (1992-1996).

MEASUREMENTS

Fasting plasma glucose (FPG) was measured in 1019 women and 636 men. Two-hour glucose (2HG) levels after a 75 g oral glucose tolerance test were also available (women, n=870; men, n=559). Dominant hand grip strength was assessed using a hand-held dynamometer at 3.0±1.6 visits over a median 7.0 years. Mixed linear models examined the association of baseline glucose levels with grip strength, accounting for repeated visits, and adjusting for covariates.

RESULTS

Sex-specific FPG quartiles were associated with unadjusted differences in grip strength among women (p=0.03) but not men (p=0.50). However, in men, adjusting for age, education, height, weight, peripheral neuropathy, physical activity, and comorbidities, each SD (SD=17 mg/dL) higher FPG was associated with persistently lower grip strength (-0.44±0.22 kg, p=0.049); 2HG (SD=50 mg/dL) was unrelated to grip strength (-0.39±0.25 kg, p=0.13). In women, neither FPG (SD=16 mg/dL) nor 2HG (SD=45 mg/dL) was associated with grip strength (0.02±0.12 kg, p=0.90; and -0.20±0.14 kg, p=0.14; respectively) after adjustment. The rate of change in grip strength did not differ across FPG or 2HG quartiles in either sex.

CONCLUSIONS

In age-adjusted analyses, elevated fasting glucose levels are associated with persistently lower grip strength in older men, but not women. Future studies are needed to elucidate reasons for these sex differences and may provide further insight into accelerated loss of muscle function as a complication of diabetes in older adults.

Diabetes. Excess risk of stroke in women--the role of diabetes mellitus

A growing body of literature examines the burden of sex-specific risk factors for cardiovascular disease. Women with diabetes mellitus have a higher risk of coronary heart disease than men with diabetes mellitus. A recent study provides strong evidence that women with diabetes mellitus also have an increased risk of stroke.

Gender differences and disparities in all-cause and coronary heart disease mortality: epidemiological aspects

This overview is primarily concerned with large recent prospective cohort studies of adult populations, not patients, because the latter studies are confounded by differences in medical and surgical management for men vs. women. When early papers are uniquely informative they are also included. Because the focus is on epidemiology, details of age, sex, sample size, and source as well as study methods are provided. Usually the primary outcomes were all-cause or coronary heart disease (CHD) mortality using baseline data from midlife or older adults. Fifty years ago few prospective cohort studies of all-cause or CHD mortality included women. Most epidemiologic studies that included community-dwelling adults did not include both sexes and still do not report men and women separately. Few studies consider both sex (biology) and gender (behavior and environment) differences. Lifespan studies describing survival after live birth are not considered here. The important effects of prenatal and early childhood biologic and behavioral factors on adult mortality are beyond the scope of this review. Clinical trials are not discussed. Overall, presumptive evidence for causality was equivalent for psychosocial and biological exposures, and these attributes were often associated with each other. Inconsistencies or gaps were particularly obvious for studies of sex or gender differences in age and optimal measures of body size for CHD outcomes, and in the striking interface of diabetes and people with the metabolic syndrome, most of whom have unrecognized diabetes.