Nonlinear modeling of oral glucose tolerance test response to evaluate associations with aging outcomes

As people age, their ability to maintain homeostasis in response to stressors diminishes. Physical frailty, a syndrome characterized by loss of resilience to stressors, is thought to emerge due to dysregulation of and breakdowns in communication among key physiological systems. Dynamical systems modeling of these physiological systems aims to model the underlying processes that govern response to stressors. We hypothesize that dynamical systems model summaries are predictive of age-related declines in health and function. In this study, we analyze data obtained during 75-gram oral-glucose tolerance tests (OGTT) on 1,120 adults older than 50 years of age from the Baltimore Longitudinal Study on Aging. We adopt a two-stage modeling approach. First, we fit OGTT curves with the Ackerman model-a nonlinear, parametric model of the glucose-insulin system-and with functional principal components analysis. We then fit linear and Cox proportional hazards models to evaluate whether usual gait speed and survival are associated with the stage-one model summaries. We also develop recommendations for identifying inadequately-fitting nonlinear model fits in a cohort setting with numerous heterogeneous response curves. These recommendations include: (1) defining a constrained parameter space that ensures biologically plausible model fits, (2) evaluating the relative discrepancy between predicted and observed responses of biological interest, and (3) identifying model fits that have notably poor model fit summary measures, such as [Formula: see text], relative to other fits in the cohort. The Ackerman model was unable to adequately fit 36% of the OGTT curves. The stage-two regression analyses found no associations between Ackerman model summaries and usual gait speed, nor with survival. The second functional principal component score was associated with faster gait speed (p<0.01) and improved survival (p<0.01).

Diabetes, SGLT-2 Inhibitors, and Urinary Tract Infection: a Review

PURPOSE OF REVIEW

The aim of this review is to focus on epidemiology, pathogenesis, risk factors, management, and complications of UTI in people with diabetes as well as reviewing the association of SGLT-2 inhibitors with genitourinary infections.

RECENT FINDINGS

Individuals diagnosed with T2DM are more prone to experiencing UTIs and recurrent UTIs compared to individuals without T2DM. T2DM is associated with an increased risk of any genitourinary infections (GUI), urinary tract infections (UTIs), and genital infections (GIs) across all age categories. SGLT2 inhibitors are a relatively new class of anti-hyperglycemic agents, and studies suggest that they are associated with an increased risk of genitourinary infections. The management of diabetes and lifestyle modifications with a patient-centric approach are the most recognized methods for preventing critical long-term complications including genitourinary manifestations of diabetes. The available data regarding the association of SGLT-2 inhibitors with genitourinary infections is more comprehensive compared to that with UTIs. Further research is needed to better understand the mechanisms underlining the association between SGLT-2 inhibitors and genital infections and UTIs.

Sex Specific Associations of Sex hormone With Brain Volumes and Cerebral Blood Flow: A Cross Sectional Observational Study Within the Look AHEAD Type 2 Diabetes Cohort

Background

Females have greater brain volume and cerebral blood flow than males when controlling for intracranial volume and age. Brain volume decreases after menopause, suggesting a role of sex hormones. We studied the association of sex hormones with brain volume, white matter hyperintensity volumes and cerebral blood flow in people with Type 2 Diabetes and with overweight and obesity conditions that accelerate brain atrophy.

Methods

We analyzed data from 215 participants with overweight or obesity and Type 2 Diabetes from the Look AHEAD Brain Magnetic Resonance Imaging ancillary study (mean age 68 years, 73% postmenopausal female). Estradiol and total testosterone levels were measured with electrochemoluminescence assays. The ratio of brain measurements to intracranial volume was analyzed to account for body size. We analyzed sex hormones as quantitative measures in males, whereas in females we grouped those with detectable vs. undetectable hormone levels (Estradiol <73 pmol/L [20 pg/mL]: 79%; Total Testosterone < 0.07 mmol/L [0.02 ng/mL]: 37% undetectable in females).

Results

Females with detectable total testosterone levels had higher brain volume to intracranial volume ratio (median [25th, 75th percentile]: 0.85 [0.84, 0.86]) as compared to those with undetectable Total Testosterone levels (0.84 [0.83, 0.86]; rank sum p=0.04). This association was attenuated after age and body mass index adjustment (p=0.08). Neither white matter hyperintensity volumes or cerebral blood flow in females, nor any brain measures in males, were significantly associated with Estradiol or Total Testosterone.

Conclusions

In postmenopausal females with Type 2 Diabetes with overweight and obesity, detectable levels of total testosterone were associated greater brain volume relative to intracranial volume, suggesting a protective role for testosterone in female brain health. Our findings are limited by a small sample size and low sensitivity of hormone assays. Our suggestive findings can be combined with future larger studies to assess clinically important differences.

Trial Registration

NCT00017953.

Prioritizing Patient Experiences in the Management of Diabetes and Its Complications: An Endocrine Society Position Statement

Diabetes can be an arduous journey both for people with diabetes (PWD) and their caregivers. While the journey of every person with diabetes is unique, common themes emerge in managing this disease. To date, the experiences of PWD have not been fully considered to successfully implement the recommended standards of diabetes care in practice. It is critical for health-care providers (HCPs) to recognize perspectives of PWD to achieve optimal health outcomes. Further, existing tools are available to facilitate patient-centered care but are often underused. This statement summarizes findings from multistakeholder expert roundtable discussions hosted by the Endocrine Society that aimed to identify existing gaps in the management of diabetes and its complications and to identify tools needed to empower HCPs and PWD to address their many challenges. The roundtables included delegates from professional societies, governmental organizations, patient advocacy organizations, and social enterprises committed to making life better for PWD. Each section begins with a clinical scenario that serves as a framework to achieve desired health outcomes and includes a discussion of resources for HCPs to deliver patient-centered care in clinical practice. As diabetes management evolves, achieving this goal will also require the development of new tools to help guide HCPs in supporting PWD, as well as concrete strategies for the efficient uptake of these tools in clinical practice to minimize provider burden. Importantly, coordination among various stakeholders including PWD, HCPs, caregivers, policymakers, and payers is critical at all stages of the patient journey.

CO2 cerebrovascular reactivity measured with CBF-MRI in older individuals: Association with cognition, physical function, amyloid, and tau proteins

Vascular pathology is the second leading cause of cognitive impairment and represents a major contributing factor in mixed dementia. However, biomarkers for vascular cognitive impairment and dementia (VCID) are under-developed. Here we aimed to investigate the potential role of CO2 Cerebrovascular Reactivity (CVR) measured with phase-contrast quantitative flow MRI in cognitive impairment and dementia. Forty-five (69 ± 7 years) impaired (37 mild-cognitive-impairment and 8 mild-dementia by syndromic diagnosis) and 22 cognitively-healthy-control (HC) participants were recruited and scanned on a 3 T MRI. Biomarkers of AD pathology were measured in cerebrospinal fluid. We found that CBF-CVR was lower (p = 0.027) in the impaired (mean±SE, 3.70 ± 0.15%/mmHg) relative to HC (4.28 ± 0.21%/mmHg). After adjusting for AD pathological markers (Aβ42/40, total tau, and Aβ42/p-tau181), higher CBF-CVR was associated with better cognitive performance, including Montreal Cognitive Assessment, MoCA (p = 0.001), composite cognitive score (p = 0.047), and language (p = 0.004). Higher CBF-CVR was also associated with better physical function, including gait-speed (p = 0.006) and time for five chair-stands (p = 0.049). CBF-CVR was additionally related to the Clinical-Dementia-Rating, CDR, including global CDR (p = 0.026) and CDR Sum-of-Boxes (p = 0.015). CBF-CVR was inversely associated with hemoglobin A1C level (p = 0.017). In summary, CBF-CVR measured with phase-contrast MRI shows associations with cognitive performance, physical function, and disease-severity, independent of AD pathological markers.

Type 2 Diabetes Modifies the Association of CAD Genomic Risk Variants With Subclinical Atherosclerosis

BACKGROUND

Individuals with type 2 diabetes (T2D) have an increased risk of coronary artery disease (CAD), but questions remain about the underlying pathology. Identifying which CAD loci are modified by T2D in the development of subclinical atherosclerosis (coronary artery calcification [CAC], carotid intima-media thickness, or carotid plaque) may improve our understanding of the mechanisms leading to the increased CAD in T2D.

METHODS

We compared the common and rare variant associations of known CAD loci from the literature on CAC, carotid intima-media thickness, and carotid plaque in up to 29 670 participants, including up to 24 157 normoglycemic controls and 5513 T2D cases leveraging whole-genome sequencing data from the Trans-Omics for Precision Medicine program. We included first-order T2D interaction terms in each model to determine whether CAD loci were modified by T2D. The genetic main and interaction effects were assessed using a joint test to determine whether a CAD variant, or gene-based rare variant set, was associated with the respective subclinical atherosclerosis measures and then further determined whether these loci had a significant interaction test.

RESULTS

Using a Bonferroni-corrected significance threshold of P<1.6×10-4, we identified 3 genes (ATP1B1, ARVCF, and LIPG) associated with CAC and 2 genes (ABCG8 and EIF2B2) associated with carotid intima-media thickness and carotid plaque, respectively, through gene-based rare variant set analysis. Both ATP1B1 and ARVCF also had significantly different associations for CAC in T2D cases versus controls. No significant interaction tests were identified through the candidate single-variant analysis.

CONCLUSIONS

These results highlight T2D as an important modifier of rare variant associations in CAD loci with CAC.

WHOLE GENOME SEQUENCING ANALYSIS OF BODY MASS INDEX IDENTIFIES NOVEL AFRICAN ANCESTRY-SPECIFIC RISK ALLELE

Obesity is a major public health crisis associated with high mortality rates. Previous genome-wide association studies (GWAS) investigating body mass index (BMI) have largely relied on imputed data from European individuals. This study leveraged whole-genome sequencing (WGS) data from 88,873 participants from the Trans-Omics for Precision Medicine (TOPMed) Program, of which 51% were of non-European population groups. We discovered 18 BMI-associated signals (P < 5 × 10-9). Notably, we identified and replicated a novel low frequency single nucleotide polymorphism (SNP) in MTMR3 that was common in individuals of African descent. Using a diverse study population, we further identified two novel secondary signals in known BMI loci and pinpointed two likely causal variants in the POC5 and DMD loci. Our work demonstrates the benefits of combining WGS and diverse cohorts in expanding current catalog of variants and genes confer risk for obesity, bringing us one step closer to personalized medicine.

A Study of Physical Resilience and Aging (SPRING): Conceptual framework, rationale, and study design

Understanding the physiological basis of physical resilience to clinical stressors is crucial for the well-being of older adults. This article presents a novel framework to discover the biological underpinnings of physical resilience in older adults as part of the "Characterizing Resiliencies to Physical Stressors in Older Adults: A Dynamical Physiological Systems Approach" study, also known as The Study of Physical Resilience and Aging (SPRING). Physical resilience, defined as the capacity of a person to withstand clinical stressors and quickly recover or improve upon a baseline functional level, is examined in adults aged 55 years and older by studying the dynamics of stress response systems. The hypothesis is that well-regulated stress response systems promote physical resilience. The study employs dynamic stimulation tests to assess energy metabolism, the hypothalamic-pituitary-adrenal axis, the autonomic nervous system, and the innate immune system. Baseline characteristics influencing resilience outcomes are identified through deep phenotyping of physical and cognitive function, as well as of biological, environmental, and psychosocial characteristics. SPRING aims to study participants undergoing knee replacement surgery (n = 100), bone and marrow transplantation (n = 100), or anticipating dialysis initiation (n = 60). Phenotypic and functional measures are collected pre-stressor and at multiple times after stressor for up to 12 months to examine resilience trajectories. By improving our understanding of physical resilience in older adults, SPRING has the potential to enhance resilient outcomes to major clinical stressors. The article provides an overview of the study's background, rationale, design, pilot phase, implementation, and implications for improving the health and well-being of older adults.

Hormones and Aging: An Endocrine Society Scientific Statement

Multiple changes occur across various endocrine systems as an individual ages. The understanding of the factors that cause age-related changes and how they should be managed clinically is evolving. This statement reviews the current state of research in the growth hormone, adrenal, ovarian, testicular, and thyroid axes, as well as in osteoporosis, vitamin D deficiency, type 2 diabetes, and water metabolism, with a specific focus on older individuals. Each section describes the natural history and observational data in older individuals, available therapies, clinical trial data on efficacy and safety in older individuals, key points, and scientific gaps. The goal of this statement is to inform future research that refines prevention and treatment strategies in age-associated endocrine conditions, with the goal of improving the health of older individuals.

Adiposity, aldosterone and plasma renin activity among African Americans: The Jackson Heart Study

Objective

To analyze associations between adiposity and the renin-angiotensin-aldosterone system (RAAS) in a large African American (AA) cohort.

Methods

Cross-sectional associations of adiposity (body mass index [BMI], waist circumference [WC], waist:height ratio, waist:hip ratio, leptin, adiponectin, leptin:adiponectin ratio [LAR], subcutaneous [SAT] and visceral adipose tissue [VAT], and liver attenuation [LA]) with aldosterone, plasma renin activity (renin), and aldosterone:renin ratio (ARR) were assessed in the Jackson Heart Study using adjusted linear regression models.

Results

A 1-SD higher BMI was associated with a 4.8 % higher aldosterone, 9.4 % higher renin, and 5.0 % lower ARR (all p < 0.05). Log-leptin had the largest magnitude of association with renin (30.2 % higher) and ARR (9.6 % lower), while the strongest association of aldosterone existed for log-LAR (15.3 % higher) (all 1-SD, p < 0.05). SAT was only associated with renin. VAT was associated with higher aldosterone, renin, and ARR. Liver fat was associated with aldosterone and renin, but not ARR. Associations of WC, BMI, and SAT with aldosterone were greater in men while the association with VAT was greater in women (p-interactions < 0.05).

Conclusion

Multiple measures of adiposity are associated with the RAAS in AAs. Further studies should examine the role of RAAS in obesity-driven cardiometabolic diseases.

Investigating Gene-Diet Interactions Impacting the Association Between Macronutrient Intake and Glycemic Traits

Few studies have demonstrated reproducible gene-diet interactions (GDIs) impacting metabolic disease risk factors, likely due in part to measurement error in dietary intake estimation and insufficient capture of rare genetic variation. We aimed to identify GDIs across the genetic frequency spectrum impacting the macronutrient-glycemia relationship in genetically and culturally diverse cohorts. We analyzed 33,187 participants free of diabetes from 10 National Heart, Lung, and Blood Institute Trans-Omics for Precision Medicine program cohorts with whole-genome sequencing, self-reported diet, and glycemic trait data. We fit cohort-specific, multivariable-adjusted linear mixed models for the effect of diet, modeled as an isocaloric substitution of carbohydrate for fat, and its interactions with common and rare variants genome-wide. In main effect meta-analyses, participants consuming more carbohydrate had modestly lower glycemic trait values (e.g., for glycated hemoglobin [HbA1c], -0.013% HbA1c/250 kcal substitution). In GDI meta-analyses, a common African ancestry-enriched variant (rs79762542) reached study-wide significance and replicated in the UK Biobank cohort, indicating a negative carbohydrate-HbA1c association among major allele homozygotes only. Simulations revealed that >150,000 samples may be necessary to identify similar macronutrient GDIs under realistic assumptions about effect size and measurement error. These results generate hypotheses for further exploration of modifiable metabolic disease risk in additional cohorts with African ancestry.

ARTICLE HIGHLIGHTS

We aimed to identify genetic modifiers of the dietary macronutrient-glycemia relationship using whole-genome sequence data from 10 Trans-Omics for Precision Medicine program cohorts. Substitution models indicated a modest reduction in glycemia associated with an increase in dietary carbohydrate at the expense of fat. Genome-wide interaction analysis identified one African ancestry-enriched variant near the FRAS1 gene that may interact with macronutrient intake to influence hemoglobin A1c. Simulation-based power calculations accounting for measurement error suggested that substantially larger sample sizes may be necessary to discover further gene-macronutrient interactions.

The Role of Aldosterone and Ideal Cardiovascular Health in Incident Cardiovascular Disease: The Jackson Heart Study

Background

Higher levels of ideal cardiovascular health (ICH) are associated with lower levels of aldosterone and incidence of cardiovascular disease (CVD). However, the degree to which aldosterone mediates the association between ICH and CVD incidence has not been explored. Thus, we investigated the mediational role of aldosterone in the association of 5 components of ICH (cholesterol, body mass index (BMI), physical activity, diet and smoking) with incident CVD and the mediational role of blood pressure (BP) and glucose in the association of aldosterone with incident CVD in a cohort of African Americans (AA).

Methods

The Jackson Heart Study is a prospective cohort of AAs adults with data on CVD outcomes. Aldosterone, ICH metrics and baseline characteristics were collected at exam 1 (2000-2004). ICH score was developed by summing 5 ICH metrics (smoking, dietary intake, physical activity, BMI, and total cholesterol) and grouped into two categories (0-2 and ≥3 metrics). Incident CVD was defined as stroke, coronary heart disease, or heart failure. Cox proportional hazard regression models were used to model the association of categorical ICH score with incident CVD. The R Package Mediation was utilized to examine: 1) The mediational role of aldosterone in the association of ICH with incident CVD and 2) The mediational role of blood pressure and glucose in the association of aldosterone with incident CVD.

Results

Among 3,274 individuals (mean age: 54±12.4 years, 65% female), there were 368 cases of incident CVD over a median of 12.7 years. The risk of incident CVD was 46% lower (HR: 0.54; 95%CI 0.36, 0.80) in those with ≥3 ICH metrics at baseline compared to 0-2. Aldosterone mediated 5.4% (p = 0.006) of the effect of ICH on incident CVD. A 1-unit increase in log-aldosterone was associated with a 38% higher risk of incident CVD (HR 1.38, 95%CI: 1.19, 1.61) with BP and glucose mediating 25.6% (p<0.001) and 4.8% (p = 0.048), respectively.

Conclusion

Aldosterone partially mediates the association of ICH with incident CVD and both blood pressure and glucose partially mediate the association of aldosterone with incident CVD, emphasizing the potential importance of aldosterone and ICH in risk of CVD among AAs.

Abstract P153: Intensive Lifestyle Intervention in Type 2 Diabetes Mellitus Results in a More Favorable Sex Hormone Profile in Both Post-Menopausal Females and Older Males (The Look AHEAD Trial Sex Hormone Study)

Background: Prior studies showed an association between some adverse cardiometabolic outcomes and lower testosterone in males and higher estrogen in both males and post-menopausal females. However, few studies of sex hormones focused on people with type 2 diabetes (T2DM), assessed hormone changes over time or applied highly sensitive laboratory assays. Given the importance of lifestyle modification (i.e., diet, exercise and weight loss) in preventing cardiometabolic complications in people with T2DM, we examined the impact of an Intensive Lifestyle Intervention (ILI) on sex hormones over time and differences by sex.

Methods: The Look AHEAD (Action for Health in Diabetes) Study was a randomized control trial of 5,145 individuals with BMI ≥25 and T2D to evaluate the effect of ILI compared to the Diabetes Support and Education (DSE) control group on incident cardiovascular events. We selected a sample of 472 males and 426 post-menopausal female participants (mean age 60 years [SD 6.3], 20.5% Black) to examine sex hormones (estradiol - E2, total testosterone - T) and sex hormone binding globulin (SHBG) at baseline and year 1. E2 and T were measured using mass spectrometry analysis and SHBG was measured using an immunoassay.

Results: In males, ILI increased SHBG by 17.3% and T by 10.6% compared to the DSE group (Table). In postmenopausal females, ILI increased SHBG by 12.0% and decreased E2 by 23.4% compared to the DSE group (Table). The change in the sex hormone levels from baseline to 1-year follow up was attenuated when adjusted for change in BMI.

Conclusion: ILI resulting in weight loss increased T in males and decreased E2 in postmenopausal females and increased SHBG in both sexes. We plan further analysis with a larger sample and longer follow-up to examine the role of weight loss either as a co-occurring metabolic process or as a mediator for the change in sex hormones to better understand the impact of lifestyle changes and sex diffrences.

Abstract P103: Associations Between Brain Volumes and Cerebral Blood Flow and Sex Hormones in the Look AHEAD Brain MRI Cohort

Background: Females have greater relative brain volume (BV) and cerebral blood flow (CBF) compared to males. BV decreases after menopause suggesting a possible role of sex hormones. We studied the association of BV, abnormal white matter hyperintensity volumes (WMHV) and cerebral blood flow (CBF) with sex hormones in adults with type 2 diabetes (T2DM), which is associated with risk of brain atrophy.

Methods: The sample was 215 participants with overweight or obesity and T2DM from the Look AHEAD Brain MRI cohort (mean age 68 years [SD: 6.3], 27% male, 73% female [all postmenopausal]; without exogenous hormones), who had brain MRIs to evaluate their total BV, WMHV and CBF. The ratio of brain measurements to intracranial volume was analyzed to account for body size. Estradiol (E2) and testosterone levels (T) were estimated with electrochemoluminescence assays. In females, who have low E2 and T levels, we compared brain measures in those with detectable (vs. undetectable) hormone levels (E2<20 pg/mL, 79%; T<0.02 pg/mL, 37%). In males, we used Spearman correlation to assess the association between brain measures and sex hormone levels. The associations between BV, WMHV and E2 and T were adjusted for age and BMI using linear regression.

Results: Females with detectable (vs. undetectable) T levels had higher BV (p=0.04) (Table), which was attenuated after adjustment for age and BMI. WMHV and CBF were not statistically associated with sex hormone levels in females. In males, no brain measures were significantly associated with sex hormones levels.

Conclusions: In postmenopausal females with T2DM, detectable levels of T were associated greater BV, but not associated any CBF or WMHV. In males, none of the brain measures were associated with sex hormones. Our findings are limited by a small, convenient sample size and low sensitivity of hormone assays with a high proportion of undetectable levels. Our findings suggest that larger samples with high sensitivity hormone assays are needed to assess clinically important differences.

Omega-3 Fatty Acids in Cardiovascular Disease and Diabetes: a Review of Recent Evidence

PURPOSE OF REVIEW

Omega-3 fatty acids (n-3 FA) lower triglycerides, have anti-inflammatory properties, and improve metabolism. Clinical evidence of cardiovascular benefit with omega-3 fatty acids is mixed. We discuss mechanisms providing biological plausibility of benefit of omega-3 fatty acids in cardiovascular risk reduction and review clinical trials investigating the benefits of prescription omega-3 fatty acids in dyslipidemia, atherosclerotic cardiovascular disease (ASCVD), and diabetes.

RECENT FINDINGS

Although early trials showed no benefit of omega-3 fatty acids in ASCVD, the REDUCE-IT trial noted significant risk reduction in ASCVD events with highly purified EPA (icosapent ethyl) use which has changed the landscape for currently available therapeutic options. However, other large trials like STRENGTH and VITAL, which used different formulations of prescription omega-3 fatty acids, did not note significant cardiovascular risk reduction. Thus the effectiveness of omega-3 fatty acids for cardiovascular disease prevention is an ongoing topic of debate. A relative paucity of studies examining benefits for glycemic outcomes in persons with diabetes exists; however, few studies have suggested lack of benefit to date. Significant residual cardiovascular risk exists for individuals with hypertriglyceridemia. Prescription omega-3 fatty acids are more commonly used for CV risk reduction in these patients. Clinical guideline statements now recommend icosapent ethyl use for selected individuals with hypertriglyceridemia to reduce cardiovascular events given recent evidence from the REDUCE-IT trial. Nonetheless, data from other large scale trials has been mixed, and future research is needed to better understand how different preparations of omega-3 may differ in their cardiovascular and metabolic effects, and the mechanisms for their benefit.

Whole-exome sequence analysis of anthropometric traits illustrates challenges in identifying effects of rare genetic variants

Anthropometric traits, measuring body size and shape, are highly heritable and significant clinical risk factors for cardiometabolic disorders. These traits have been extensively studied in genome-wide association studies (GWASs), with hundreds of genome-wide significant loci identified. We performed a whole-exome sequence analysis of the genetics of height, body mass index (BMI) and waist/hip ratio (WHR). We meta-analyzed single-variant and gene-based associations of whole-exome sequence variation with height, BMI, and WHR in up to 22,004 individuals, and we assessed replication of our findings in up to 16,418 individuals from 10 independent cohorts from Trans-Omics for Precision Medicine (TOPMed). We identified four trait associations with single-nucleotide variants (SNVs; two for height and two for BMI) and replicated the LECT2 gene association with height. Our expression quantitative trait locus (eQTL) analysis within previously reported GWAS loci implicated CEP63 and RFT1 as potential functional genes for known height loci. We further assessed enrichment of SNVs, which were monogenic or syndromic variants within loci associated with our three traits. This led to the significant enrichment results for height, whereas we observed no Bonferroni-corrected significance for all SNVs. With a sample size of ∼20,000 whole-exome sequences in our discovery dataset, our findings demonstrate the importance of genomic sequencing in genetic association studies, yet they also illustrate the challenges in identifying effects of rare genetic variants.

Diabetes-associated thigh muscle degeneration mediates knee osteoarthritis-related outcomes: results from a longitudinal cohort study

OBJECTIVES

We examined the association between diabetes mellitus (DM) and longitudinal MRI biomarkers for thigh muscle degeneration in patients with knee osteoarthritis (KOA) and their mediatory role in worsening KOA-related symptoms.

METHODS

The Osteoarthritis Initiative (OAI) participants with radiographic KOA (Kellgren-Lawrence grade ≥ 2) were included. Thighs and corresponding knees of KOA patients with versus without self-reported DM were matched for potential confounders using propensity score (PS) matching. We developed and used a validated deep learning method for longitudinal thigh segmentation. We assessed the association of DM with 4-year longitudinal muscle degeneration in biomarkers of muscle cross-sectional area (CSA) and contractile percentage (non-fat CSA/total CSA). We further investigated whether DM is associated with 9-year risk of KOA radiographic progression, knee replacement (KR), and symptoms worsening. Finally, we evaluated whether the DM-KOA worsening association is mediated through preceding muscle degeneration.

RESULTS

After PS matching, 698 thighs/knees were included (185:513 with:without DM; average ± SD age:64 ± 8-years; female/male:1.4). Baseline DM was associated with a decreased contractile percent of total thigh muscles and quadriceps (mean difference, 95%CI -0.16%/year, -0.25 to -0.07, and -0.21%/year, -0.33 to -0.08). DM was also associated with an increased risk of worsening KOA-related symptoms (hazard ratio, 95%CI 1.70, 1.18-2.46) but not radiographic progression or KR. The decrease in quadriceps contractile percent partially mediated the increased risk of symptoms worsening in patients with DM.

CONCLUSIONS

Baseline DM is associated with thigh muscle degeneration and KOA-related symptoms worsening. As a potentially modifiable risk factor, DM-associated longitudinal thigh muscle degeneration may partially mediate the symptoms worsening in patients with DM and coexisting KOA.

KEY POINTS

• Diabetes mellitus (DM) is associated with worsening knee osteoarthritis (KOA)-related symptoms. • As a potentially modifiable factor, DM-associated thigh muscle (quadriceps) degeneration partially mediates the worsening of KOA-related symptoms.

Powerful, scalable and resource-efficient meta-analysis of rare variant associations in large whole genome sequencing studies

Meta-analysis of whole genome sequencing/whole exome sequencing (WGS/WES) studies provides an attractive solution to the problem of collecting large sample sizes for discovering rare variants associated with complex phenotypes. Existing rare variant meta-analysis approaches are not scalable to biobank-scale WGS data. Here we present MetaSTAAR, a powerful and resource-efficient rare variant meta-analysis framework for large-scale WGS/WES studies. MetaSTAAR accounts for relatedness and population structure, can analyze both quantitative and dichotomous traits and boosts the power of rare variant tests by incorporating multiple variant functional annotations. Through meta-analysis of four lipid traits in 30,138 ancestrally diverse samples from 14 studies of the Trans Omics for Precision Medicine (TOPMed) Program, we show that MetaSTAAR performs rare variant meta-analysis at scale and produces results comparable to using pooled data. Additionally, we identified several conditionally significant rare variant associations with lipid traits. We further demonstrate that MetaSTAAR is scalable to biobank-scale cohorts through meta-analysis of TOPMed WGS data and UK Biobank WES data of ~200,000 samples.

A framework for detecting noncoding rare-variant associations of large-scale whole-genome sequencing studies

Large-scale whole-genome sequencing studies have enabled analysis of noncoding rare-variant (RV) associations with complex human diseases and traits. Variant-set analysis is a powerful approach to study RV association. However, existing methods have limited ability in analyzing the noncoding genome. We propose a computationally efficient and robust noncoding RV association detection framework, STAARpipeline, to automatically annotate a whole-genome sequencing study and perform flexible noncoding RV association analysis, including gene-centric analysis and fixed window-based and dynamic window-based non-gene-centric analysis by incorporating variant functional annotations. In gene-centric analysis, STAARpipeline uses STAAR to group noncoding variants based on functional categories of genes and incorporate multiple functional annotations. In non-gene-centric analysis, STAARpipeline uses SCANG-STAAR to incorporate dynamic window sizes and multiple functional annotations. We apply STAARpipeline to identify noncoding RV sets associated with four lipid traits in 21,015 discovery samples from the Trans-Omics for Precision Medicine (TOPMed) program and replicate several of them in an additional 9,123 TOPMed samples. We also analyze five non-lipid TOPMed traits.

Associations of Cardiometabolic Multimorbidity With All-Cause and Coronary Heart Disease Mortality Among Black Adults in the Jackson Heart Study

IMPORTANCE

A combination of diabetes, coronary heart disease (CHD), and stroke has multiplicative all-cause mortality risk compared with any individual morbidity in White populations, but there is a lack of studies in Black populations in the US.

OBJECTIVE

To examine the association of cardiometabolic multimorbidity (diabetes, stroke, and CHD) individually and collectively with all-cause and CHD mortality.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study included Black adults in the Jackson Heart Study followed over a median of 15 years. Baseline examinations were performed between 2000 and 2004, with follow-up on all-cause and CHD mortality through May 31, 2018. Participants were categorized into mutually exclusive groups at baseline: (1) free of cardiometabolic morbidity, (2) diabetes, (3) CHD, (4) stroke, (5) diabetes and stroke, (6) CHD and stroke, (7) diabetes and CHD, and (8) diabetes, stroke, and CHD. Data were analyzed from 2019 to 2021.

EXPOSURE

Cardiometabolic disease alone or in combination.

MAIN OUTCOMES AND MEASURES

The main outcomes were all-cause mortality and CHD mortality. Cox models estimated hazard ratios (HRs) with 95% CIs adjusted for sociodemographic and cardiovascular risk factors.

RESULTS

Among 5064 participants (mean [SD] age, 55.4 [12.8] years; 3200 [63%] women) in the Jackson Heart Study, 897 (18%) had diabetes, 192 (4%) had CHD, and 104 (2%) had a history of stroke. Among participants with cardiometabolic morbidities, the crude all-cause mortality rates were lowest for diabetes alone (24.4 deaths per 1000 person-years) and highest for diabetes, CHD, and stroke combined (84.1 deaths per 1000 person-years). For people with only 1 cardiometabolic morbidity, risk for all-cause mortality was highest for people with stroke (HR, 1.74; 95% CI, 1.24-2.42), followed by CHD (HR, 1.59 (95% CI, 1.22-2.08) and diabetes (HR, 1.50; 95% CI, 1.22-1.85), compared with no cardiometabolic morbidities. There were also increased risks of mortality with combinations of diabetes and stroke (HR, 1.71; 95% CI, 1.09-2.68), CHD and stroke (HR, 2.23; 95% CI, 1.35-3.69), and diabetes and CHD (HR, 2.28; 95% CI, 1.65-3.15). The combination of diabetes, stroke, and CHD was associated with the highest all-cause mortality (HR, 3.68; 95% CI, 1.96-6.93). Findings were similar for CHD mortality, but with a larger magnitude of association (eg, diabetes, stroke, and CHD: HR, 13.52; 95% CI, 3.38-54.12).

CONCLUSIONS AND RELEVANCE

In this cohort study, an increasing number of cardiometabolic multimorbidities was associated with a multiplicative increase in risk of all-cause mortality among Black adults, with a greater magnitude of association for CHD mortality.

Whole genome sequence association analysis of fasting glucose and fasting insulin levels in diverse cohorts from the NHLBI TOPMed program

The genetic determinants of fasting glucose (FG) and fasting insulin (FI) have been studied mostly through genome arrays, resulting in over 100 associated variants. We extended this work with high-coverage whole genome sequencing analyses from fifteen cohorts in NHLBI's Trans-Omics for Precision Medicine (TOPMed) program. Over 23,000 non-diabetic individuals from five race-ethnicities/populations (African, Asian, European, Hispanic and Samoan) were included. Eight variants were significantly associated with FG or FI across previously identified regions MTNR1B, G6PC2, GCK, GCKR and FOXA2. We additionally characterize suggestive associations with FG or FI near previously identified SLC30A8, TCF7L2, and ADCY5 regions as well as APOB, PTPRT, and ROBO1. Functional annotation resources including the Diabetes Epigenome Atlas were compiled for each signal (chromatin states, annotation principal components, and others) to elucidate variant-to-function hypotheses. We provide a catalog of nucleotide-resolution genomic variation spanning intergenic and intronic regions creating a foundation for future sequencing-based investigations of glycemic traits.

Glucometabolic State Transitions: The Jackson Heart Study

Background

Diabetes and prediabetes are common among African Americans (AA), but the frequency and predictors of transition between normal, impaired glucose metabolism, and diabetes are not well-described. The aim of this study was to examine glucometabolic transitions and their association with the development of type 2 diabetes (T2D).

Methods

AA participants of the Jackson Heart Study who attended baseline exam (2000-2004) and at least one of two subsequent exams (2005-2008 and 2009-2013, ~8 years) were classified according to glycemic status. Transitions were defined as progression (deterioration) or remission (improvement) of glycemic status. Multinomial logistic regression models with repeated measures were used to estimate the odds ratios (OR) for remission and progression with adjustment for demographic, anthropometric, behavioral, and biochemical factors.

Results

Among 3353 participants, (mean age 54.6±12.3 years), 43% were normoglycemic, 32% were prediabetes, and 25% had diabetes at baseline. For those with normal glucose at a visit, the probability at the next visit (~4years) of having prediabetes or diabetes was 38.5% and 1.8%, respectively. For those with prediabetes, the probability was 9.9% to improve to normal and 19.9% to progress to diabetes. Progression was associated with baseline BMI, diabetes status, triglycerides, family history of diabetes, and weight gain (OR 1.04 kg, 95% CI:1.03-1.06, P=<.0001). Remission was strongly associated with weight loss (OR .97 kg, 95%CI: .95-.98, P<.001).

Conclusions

In AAs, glucometabolic transitions were frequent and most involved deterioration. From a public health perspective additional emphasis should be placed on weight control to preserve glucometabolic status and prevent progression to T2D.

Assessing the Pathophysiology of Hyperglycemia in the Diabetes RElated to Acute Pancreatitis and Its Mechanisms Study: From the Type 1 Diabetes in Acute Pancreatitis Consortium

OBJECTIVES

The metabolic abnormalities that lead to diabetes mellitus (DM) after an episode of acute pancreatitis (AP) have not been extensively studied. This article describes the objectives, hypotheses, and methods of mechanistic studies of glucose metabolism that comprise secondary outcomes of the DREAM (Diabetes RElated to Acute pancreatitis and its Mechanisms) Study.

METHODS

Three months after an index episode of AP, participants without preexisting DM will undergo baseline testing with an oral glucose tolerance test. Participants will be followed longitudinally in three subcohorts with distinct metabolic tests. In the first and largest subcohort, oral glucose tolerance tests will be repeated 12 months after AP and annually to assess changes in β-cell function, insulin secretion, and insulin sensitivity. In the second, mixed meal tolerance tests will be performed at 3 and 12 months, then annually, and following incident DM to assess incretin and pancreatic polypeptide responses. In the third, frequently sampled intravenous glucose tolerance tests will be performed at 3 months and 12 months to assess the first-phase insulin response and more precisely measure β-cell function and insulin sensitivity.

CONCLUSIONS

The DREAM study will comprehensively assess the metabolic and endocrine changes that precede and lead to the development of DM after AP.

Rationale and Design for the Diabetes RElated to Acute Pancreatitis and Its Mechanisms Study: A Prospective Cohort Study From the Type 1 Diabetes in Acute Pancreatitis Consortium

ABSTRACT

Acute pancreatitis (AP) is a disease characterized by an acute inflammatory phase followed by a convalescent phase. Diabetes mellitus (DM) was historically felt to be a transient phenomenon related to acute inflammation; however, it is increasingly recognized as an important late and chronic complication. There are several challenges that have prevented precisely determining the incidence rate of DM after AP and understanding the underlying mechanisms. The DREAM (Diabetes RElated to Acute Pancreatitis and its Mechanisms) Study is a prospective cohort study designed to address these and other knowledge gaps to provide the evidence needed to screen for, prevent, and treat DM after AP. In the following article, we summarize literature regarding the epidemiology of DM after AP and provide the rationale and an overview of the DREAM study.

The Relationship of Falls With Achieved 25-Hydroxyvitamin D Levels From Vitamin D Supplementation: The STURDY Trial

Context

The Study to Understand Fall Reduction and Vitamin D in You (STURDY), a randomized trial enrolling older adults with low 25-hydroxyvitamin D [25(OH)D], demonstrated vitamin D supplementation ≥ 1000 IU/day did not prevent falls compared with 200 IU/day, with doses ≥ 2000 IU/day potentially showing safety concerns.

Objective

To examine associations of achieved and change in 25(OH)D concentrations after 3 months of vitamin D supplementation with fall risk.

Design

Observational analysis of trial data.

Setting

General community.

Participants

A total of 637 adults aged ≥ 70 with baseline 25(OH)D concentrations 10 to 29 ng/mL and elevated fall risk. Three-month on-treatment absolute 25(OH)D; absolute and relative changes from baseline.

Main Outcome Measures

Incident first fall (primary) and first consequential fall (injury or sought medical care) up to 24 months. Cox models were adjusted for sociodemographics, season, Short Physical Performance Battery, and body mass index.

Results

At baseline, mean (SD) age was 77.1 (5.4) years and 25(OH)D was 22.1 (5.1) ng/mL; 43.0% were women and 21.5% non-White. A total of 395 participants experienced ≥ 1 fall; 294 experienced ≥ 1 consequential fall. There was no association between absolute achieved 25(OH)D and incident first fall (30-39 vs < 30 ng/mL hazard ratio [HR], 0.93; 95% CI, 0.74-1.16; ≥40 vs < 30 ng/mL HR, 1.09; 95% CI, 0.82-1.46; adjusted overall P = 0.67), nor absolute or relative change in 25(OH)D. For incident consequential first fall, the HR (95% CI) comparing absolute 25(OH)D ≥ 40 vs < 30 ng/mL was 1.38 (0.99-1.90).

Conclusion

Achieved 25(OH)D concentration after supplementation was not associated with reduction in falls. Risk of consequential falls may be increased with achieved concentrations ≥ 40 ng/mL.

Trial Registration

ClinicalTrials.gov: NCT02166333.

Comparison of supine and seated orthostatic hypotension assessments and their association with falls and orthostatic symptoms

BACKGROUND

Orthostatic hypotension (OH) based on a change from seated-to-standing blood pressure (BP) is often used interchangeably with supine-to-standing BP.

METHODS

The Study to Understand Fall Reduction and Vitamin D in You (STURDY) was a randomized trial of vitamin D3 supplementation and fall in adults aged ≥70 years at high risk of falls. OH was defined as a drop in systolic or diastolic BP of at least 20 or 10 mmHg, measured at pre-randomization, 3-, 12-, and 24-month visits with each of 2 protocols: seated-to-standing and supine-to-standing. Participants were asked about orthostatic symptoms, and falls were ascertained via daily fall calendar, ad hoc reporting, and scheduled interviews.

RESULTS

Among 534 participants with 993 paired supine and seated assessments (mean age 76 ± 5 years, 42% women, 18% Black), mean baseline BP was 130 ± 19/68 ± 11 mmHg; 62% had a history of high BP or hypertension. Mean BP increased 3.5 (SE, 0.4)/2.6 (SE, 0.2) mmHg from sitting to standing, but decreased with supine to standing (mean change: -3.7 [SE, 0.5]/-0.8 [SE, 0.3] mmHg; P-value < 0.001). OH was detected in 2.1% (SE, 0.5) of seated versus 15.0% (SE, 1.4) of supine assessments (P < 0.001). While supine and seated OH were not associated with falls (HR: 1.55 [0.95, 2.52] vs 0.69 [0.30, 1.58]), supine systolic OH was associated with higher fall risk (HR: 1.77 [1.02, 3.05]). Supine OH was associated with self-reported fainting, blacking out, seeing spots and room spinning in the prior month (P-values < 0.03), while sitting OH was not associated with any symptoms (P-values ≥ 0.40).

CONCLUSION

Supine OH was more frequent, associated with orthostatic symptoms, and potentially more predictive of falls than seated OH.

The effects of vitamin D supplementation on frailty in older adults at risk for falls

Background

Low serum 25-hydroxyvitamin D [25(OH)D] level is associated with a greater risk of frailty, but the effects of daily vitamin D supplementation on frailty are uncertain. This secondary analysis aimed to examine the effects of vitamin D supplementation on frailty using data from the Study To Understand Fall Reduction and Vitamin D in You (STURDY).

Methods

The STURDY trial, a two-stage Bayesian, response-adaptive, randomized controlled trial, enrolled 688 community-dwelling adults aged ≥ 70 years with a low serum 25(OH)D level (10–29 ng/mL) and elevated fall risk. Participants were initially randomized to 200 IU/d (control dose; n = 339) or a higher dose (1000 IU/d, 2000 IU/d, or 4000 IU/d; n = 349) of vitamin D3. Once the 1000 IU/d was selected as the best higher dose, other higher dose groups were reassigned to the 1000 IU/d group and new enrollees were randomized 1:1 to 1000 IU/d or control group. Data were collected at baseline, 3, 12, and 24 months. Frailty phenotype was based on number of the following conditions: unintentional weight loss, exhaustion, slowness, low activity, and weakness (≥ 3 conditions as frail, 1 or 2 as pre-frail, and 0 as robust). Cox proportional hazard models estimated the risk of developing frailty, or improving or worsening frailty status at follow-up. All models were adjusted for demographics, health conditions, and further stratified by baseline serum 25(OH)D level (insufficiency (20–29 ng/mL) vs. deficiency (10–19 ng/mL)).

Results

Among 687 participants (mean age 77.1 ± 5.4, 44% women) with frailty assessment at baseline, 208 (30%) were robust, 402 (59%) were pre-frail, and 77 (11%) were frail. Overall, there was no significant difference in risk of frailty outcomes comparing the pooled higher doses (PHD; ≥ 1000 IU/d) vs. 200 IU/d. When comparing each higher dose vs. 200 IU/d, the 2000 IU/d group had nearly double the risk of worsening frailty status (HR = 1.89, 95% CI: 1.13–3.16), while the 4000 IU/d group had a lower risk of developing frailty (HR = 0.22, 95% CI: 0.05–0.97). There were no significant associations between vitamin D doses and frailty status in the analyses stratified by baseline serum 25(OH)D level.

Conclusions

High dose vitamin D supplementation did not prevent frailty. Significant subgroup findings might be the results of type 1 error.

Trial registration

ClinicalTrials.gov: NCT02166333.

Determinants of metabolic syndrome and type 2 diabetes in the absence of obesity: The Jackson Heart Study

Context

Multiple studies suggest that adults who were normal weight at diabetes diagnosis are at higher risk for all-cause mortality than those who had overweight or obesity at diagnosis.

Objective

While obesity is a known risk factor for cardiometabolic disease, differences in body fat distribution in those without obesity are understudied, especially in African Americans.

Methods

In 1005 participants of the Jackson Heart Study, without cardiovascular disease at baseline, we used logistic regression to investigate the longitudinal association of body fat distribution by CT scan with metabolic syndrome (MetS) or type 2 diabetes (T2D). We used the harmonized International Diabetes Federation criteria to define MetS. We included only normal weight or overweight participants (BMI: 18.5 to < 30.0 kg/m²). We created separate models for MetS and T2D adjusted for a standard set of covariates. We excluded participants with prevalent MetS or T2D, respectively in sensitivity.

Results

Higher visceral fat, subcutaneous fat, BMI, and insulin resistance (HOMA-IR) were significantly associated with MetS and T2D after adjustment. Visceral fat was strongly associated with both outcomes (MetS OR = 2.07 [1.66-2.68]; T2D OR = 1.51 [1.21-1.88]), and the association for MetS persisted in the normal weight only group. Estimates were robust to sensitivity analysis and were only modestly mediated by insulin resistance. Physical activity was not associated with MetS or T2D.

Conclusion

Visceral fat is strongly associated with developing MetS, even in normal weight individuals, suggesting that excess visceral fat plays a role in cardiometabolic risk beyond that of overall adiposity and obesity in African Americans.

Rare coding variants in RCN3 are associated with blood pressure

BACKGROUND

While large genome-wide association studies have identified nearly one thousand loci associated with variation in blood pressure, rare variant identification is still a challenge. In family-based cohorts, genome-wide linkage scans have been successful in identifying rare genetic variants for blood pressure. This study aims to identify low frequency and rare genetic variants within previously reported linkage regions on chromosomes 1 and 19 in African American families from the Trans-Omics for Precision Medicine (TOPMed) program. Genetic association analyses weighted by linkage evidence were completed with whole genome sequencing data within and across TOPMed ancestral groups consisting of 60,388 individuals of European, African, East Asian, Hispanic, and Samoan ancestries.

RESULTS

Associations of low frequency and rare variants in RCN3 and multiple other genes were observed for blood pressure traits in TOPMed samples. The association of low frequency and rare coding variants in RCN3 was further replicated in UK Biobank samples (N = 403,522), and reached genome-wide significance for diastolic blood pressure (p = 2.01 × 10- 7).

CONCLUSIONS

Low frequency and rare variants in RCN3 contributes blood pressure variation. This study demonstrates that focusing association analyses in linkage regions greatly reduces multiple-testing burden and improves power to identify novel rare variants associated with blood pressure traits.

Effects of Vitamin D Supplementation on Orthostatic Hypotension: Results From the STURDY Trial

BACKGROUND

Vitamin D3 supplementation is considered a potential intervention to prevent orthostatic hypotension (OH) based on observational evidence that vitamin D levels are inversely associated with OH. With data from The Study to Understand Fall Reduction and Vitamin D in You (STURDY), a double-blind, randomized, response-adaptive trial, we determined if higher doses of vitamin D3 reduced risk of OH.

METHODS

STURDY tested the effects of higher (1,000+ IU/day, i.e., 1,000, 2,000, and 4,000 IU/day combined) vs. lower-dose vitamin D3 (200 IU/day, comparison) on fall risk in adults ages 70 years and older with low serum 25-hydroxyvitamin D (25(OH)D, 10-29 ng/ml). OH was determined at baseline, 3, 12, and 24 months by taking the difference between seated and standing blood pressure (BP). OH was defined as a drop in systolic or diastolic BP of at least 20 or 10 mm Hg after 1 minute of standing. Participants were also asked about OH symptoms during the assessment and the preceding month.

RESULTS

Among 688 participants (mean age 77 [SD, 5] years; 44% women; 18% Black), the mean baseline systolic/diastolic BP was 130 (19)/67 (11) mm Hg, serum 25(OH)D was 22.1 (5.1) ng/ml, and 2.8% had OH. There were 2,136 OH assessments over the maximum 2-year follow-up period. Compared with 200 IU/day, 1,000+ IU/day was not associated with seated, standing, or orthostatic BP, and it did not lower risk of OH or orthostatic symptoms.

CONCLUSIONS

These findings do not support use of higher doses of vitamin D3 supplementation as an intervention to prevent OH.

CLINICAL TRIALS REGISTRATION

Trial Number NCT02166333.

The Diabetes-Cardiovascular Connection in Women: Understanding the Known Risks, Outcomes, and Implications for Care

PURPOSE OF REVIEW

Cardiovascular disease (CVD) complications constitute about 50-70% of mortality in people with diabetes. However, there remains a persistently greater relative increase in CVD morbidity and mortality in women with diabetes than in their male counterparts. This review presents recent evidence for the risks, outcomes, and management implications for women with diabetes.

RECENT FINDINGS

Compared to men, women have higher BMI and more adverse cardiovascular risk profile at time of diabetes diagnosis with greater risk for coronary heart disease, stroke, vascular dementia, and heart failure. Pregnancy-specific risk factors of gestational diabetes and pre-eclampsia are associated with future type 2 diabetes (T2D) and CVD. Women with T2D may experience greater benefits than men from GLP-1 receptor agonists. Women with diabetes are at greater relative risk for CVD complications than men, with poorer outcomes, superimposed on preexisting gender disparities in social determinants of health, lower likelihood of being offered cardioprotective interventions, and enrollment in trials. Further research and the utilization of SGLT-2 inhibitors, GLP-1 receptor agonists, and other CVD prevention strategies will help reduce morbidity and mortality.

The Value of Rare Genetic Variation in the Prediction of Common Obesity in European Ancestry Populations

Polygenic risk scores (PRSs) aggregate the effects of genetic variants across the genome and are used to predict risk of complex diseases, such as obesity. Current PRSs only include common variants (minor allele frequency (MAF) ≥1%), whereas the contribution of rare variants in PRSs to predict disease remains unknown. Here, we examine whether augmenting the standard common variant PRS (PRS_common) with a rare variant PRS (PRS_rare) improves prediction of obesity. We used genome-wide genotyped and imputed data on 451,145 European-ancestry participants of the UK Biobank, as well as whole exome sequencing (WES) data on 184,385 participants. We performed single variant analyses (for both common and rare variants) and gene-based analyses (for rare variants) for association with BMI (kg/m²), obesity (BMI ≥ 30 kg/m²), and extreme obesity (BMI ≥ 40 kg/m²). We built PRSs_common and PRSs_rare using a range of methods (Clumping+Thresholding [C+T], PRS-CS, lassosum, gene-burden test). We selected the best-performing PRSs and assessed their performance in 36,757 European-ancestry unrelated participants with whole genome sequencing (WGS) data from the Trans-Omics for Precision Medicine (TOPMed) program. The best-performing PRS_common explained 10.1% of variation in BMI, and 18.3% and 22.5% of the susceptibility to obesity and extreme obesity, respectively, whereas the best-performing PRS_rare explained 1.49%, and 2.97% and 3.68%, respectively. The PRS_rare was associated with an increased risk of obesity and extreme obesity (OR_obesity = 1.37 per SD_PRS, P_obesity = 1.7x10^-85; OR_{extremeobesity} = 1.55 per SD_PRS, P_{extremeobesity} = 3.8x10^-40), which was attenuated, after adjusting for PRS_common (OR_obesity = 1.08 per SD_PRS, P_obesity = 9.8x10^-6; OR_{extremeobesity}= 1.09 per SD_PRS, P_{extremeobesity} = 0.02). When PRS_rare and PRS_common are combined, the increase in explained variance attributed to PRS_rare was small (incremental Nagelkerke R² = 0.24% for obesity and 0.51% for extreme obesity). Consistently, combining PRS_rare to PRS_common provided little improvement to the prediction of obesity (PRS_rare AUC = 0.591; PRS_common AUC = 0.708; PRS_combined AUC = 0.710). In summary, while rare variants show convincing association with BMI, obesity and extreme obesity, the PRS_rare provides limited improvement over PRS_common in the prediction of obesity risk, based on these large populations.

Obesity Partially Mediates the Diabetogenic Effect of Lowering LDL Cholesterol

OBJECTIVE

LDL cholesterol (LDLc)-lowering drugs modestly increase body weight and type 2 diabetes risk, but the extent to which the diabetogenic effect of lowering LDLc is mediated through increased BMI is unknown.

RESEARCH DESIGN AND METHODS

We conducted summary-level univariable and multivariable Mendelian randomization (MR) analyses in 921,908 participants to investigate the effect of lowering LDLc on type 2 diabetes risk and the proportion of this effect mediated through BMI. We used data from 92,532 participants from 14 observational studies to replicate findings in individual-level MR analyses.

RESULTS

A 1-SD decrease in genetically predicted LDLc was associated with increased type 2 diabetes odds (odds ratio [OR] 1.12 [95% CI 1.01, 1.24]) and BMI (β = 0.07 SD units [95% CI 0.02, 0.12]) in univariable MR analyses. The multivariable MR analysis showed evidence of an indirect effect of lowering LDLc on type 2 diabetes through BMI (OR 1.04 [95% CI 1.01, 1.08]) with a proportion mediated of 38% of the total effect (P = 0.03). Total and indirect effect estimates were similar across a number of sensitivity analyses. Individual-level MR analyses confirmed the indirect effect of lowering LDLc on type 2 diabetes through BMI with an estimated proportion mediated of 8% (P = 0.04).

CONCLUSIONS

These findings suggest that the diabetogenic effect attributed to lowering LDLc is partially mediated through increased BMI. Our results could help advance understanding of adipose tissue and lipids in type 2 diabetes pathophysiology and inform strategies to reduce diabetes risk among individuals taking LDLc-lowering medications.

Trends in Insulin Types and Devices Used by Adults With Type 2 Diabetes in the United States, 2016 to 2020

IMPORTANCE

Despite rising costs and public scrutiny devoted to insulin, less is known regarding recent trends in its ambulatory use in the United States.

OBJECTIVE

To characterize trends in ambulatory insulin use, overall and based on insulin characteristics, among adults with type 2 diabetes in the United States from January 1, 2016, through December 31, 2020.

DESIGN, SETTING, AND PARTICIPANTS

This serial cross-sectional study included patients whose data were collected in IQVIA's National Disease and Therapeutic Index (NDTI), a 2-stage, all-payer, nationally representative audit of outpatient care. Approximately 4800 physicians each calendar quarter completed a form for 2 consecutive days regarding visits for each of their patients, including diagnoses, treatments, and demographic information. Data were collected from January 2016 through December 2020.

EXPOSURES

Ambulatory use of insulin.

MAIN OUTCOMES AND MEASURES

Nationally representative projections for ambulatory use of insulin (ie, treatment visits), overall and aggregated by insulin molecule (insulins regular, neutral protamine Hagedorn [NPH], lispro, glulisine, glargine, detemir, degludec, and aspart), delivery devices (vials/syringes or pens), therapeutic class (short-acting, rapid-acting, long-acting, intermediate-acting, and premixed insulin), insulin type (human, analog, and biosimilar), and date of approval (newer: before 2010; and older: after 2010).

RESULTS

There were 27 860 691 insulin treatment visits between 2016 and 2020. Among all patient encounters that indicated use of insulin in 2020, 1 989 154 (43.9%) were among those aged 60 to 74 years; 2 372 629 (52.4%) among men; 2 646 247 (58.4%) among White patients; 811 639 (17.9%) among Black patients; and 701 912 (15.5%) among Hispanic patients. Insulin glargine was the most frequently used insulin from 2016 to 2020, accounting for approximately half of treatment visits (eg, 2020: 2.6 of 4.9 million visits; 95% CI, 2.1-3.1 million). Among insulin classes, long-acting insulin accounted for approximately two-thirds of treatment visits during this period (eg, 2020: 3.7 million visits; 95% CI, 3.0-4.4 million). Treatment visits for insulin pens increased from 36.1% in 2016 (2.2 of 6.0 million visits; 95% CI, 1.7-2.7 million) to 58.7% in 2020 (2.9 million visits; 95% CI, 2.3-3.5 million), while use of insulin vials/syringes declined in parallel. Analog insulin use predominated and accounted for more than 80% of total treatment visits across all years (eg, 2020: 4.3 million visits; 95% CI, 3.4-5.1 million). Newer insulins were increasingly used, from 18.1% of total treatment visits in 2016 (1.1 million visits; 95% CI, 0.8-1.4 million) to 40.9% in 2020 (2.0 million visits; 95% CI, 1.5-2.5 million). The use of biosimilar insulin, which was first approved in 2015, increased from 2.6% in 2017 (0.1 of 5.3 million visits; 95% CI, 0.04-0.2 million) to 8.2% in 2020 (0.4 million visits; 95% CI, 0.2-0.6 million) of total insulin treatment visits. The total number of insulin treatment visits declined from a peak of 6.0 million visits in 2016 to a nadir of 4.9 million visits in 2020 (approximately 18% decline).

CONCLUSIONS AND RELEVANCE

In this study, ambulatory insulin use in the United States during the past 5 years remained dominated by the use of insulin analogs and insulin pen delivery devices, with increasing uptake of newer products as they have been brought to market.

Association of Adiposity With Incident Diabetes Among Black Adults in the Jackson Heart Study

Background

The prognostic value of anthropometric, adipokine, and computed tomography measures of adiposity to predict diabetes in Black, specifically by normoglycemia versus prediabetes, remains incompletely understood.

Methods and Results

Among Black participants without diabetes in the JHS (Jackson Heart Study), waist circumference [WC], body mass index, adiponectin, leptin, and leptin:adiponectin ratio were standardized in sample 1 (2422 participants at baseline [2000–2004]) and WC, body mass index, visceral adipose tissue (VAT), subcutaneous adipose tissue, and liver attenuation in 1537 participants at examination 2 (2005–2008) (sample 2). Hazard ratios (HRs) for diabetes were estimated using interval‐censored Cox modeling adjusting for traditional risk factors and validated with the C index. Over 5 years, 300 and 122 incident diabetes cases occurred in sample 1 and sample 2, respectively. In sample 1 and sample 2, a 1‐SD higher log‐leptin:adiponectin ratio and VAT had the strongest associations (HR, 1.95 [95% CI, 1.67–2.27] and 1.76 [95% CI, 1.52–2.04]) and discriminatory power (C index 0.68 [95% CI, 0.64–0.71] and C index 0.67 [95% CI, 0.61–0.74]) with diabetes. The normoglycemic compared with the prediabetes group had a 1.3 to 1.9 times greater magnitude of associations with diabetes for WC, liver attenuation, and VAT (P interaction <0.10). In sample 2, C indices for WC (HR, 0.84; 95% CI, 0.73–0.95), VAT (HR, 0.91; 95% CI, 0.85–0.98), and liver attenuation (HR, 0.90; 95% CI, 0.77–1.00) were greater than HbA_1c (HR, 0.74; 95% CI, 0.57–0.90) in normoglycemia, whereas HbA_1c was best in prediabetes (HR, 0.72; 95% CI, 0.66–0.78).

Conclusions

Overall, among Black adults, multiple measures of adiposity were associated with incident diabetes with modest predictive ability. In Black patients with normoglycemia, WC, liver attenuation, and VAT may appropriately identify those at high risk for diabetes, whereas HbA_1c was the best predictor in individuals with prediabetes.

Ambulatory noninsulin treatment of type 2 diabetes mellitus in the United States, 2015 to 2019

OBJECTIVE

To examine trends in the noninsulin drug treatment of type 2 diabetes, including first- and second-line therapies on top of metformin, from 2015 to 2019.

PARTICIPANTS AND METHODS

We conducted a descriptive analysis of cross-sectional data using the IQVIA National Disease and Therapeutic Index, a nationally representative audit of ambulatory physician practices in the United States. We focused on the use of noninsulin pharmacological treatments for type 2 diabetes among individuals aged 35 years and older between January 1, 2015 and December 31, 2019. The main outcome was type 2 diabetes visits where a prescription drug was used ("treatment visit").

RESULTS

Ambulatory diabetes visits decreased from 30.1 million treatment visits in 2015 to 29.5 million treatment visits in 2019. Among treatment visits where a single drug was prescribed, the use of metformin declined from 57.0% of monotherapy in 2015 to 46.0% of monotherapy in 2019, while during the same period the share of monotherapy accounted for by glucagon-like peptide-1 (GLP-1) receptor agonists increased from 4.3% to 8.5% and the share accounted for by sodium-glucose cotransporter-2 (SGLT2) inhibitors increased from 7.3% to 19.5%. Among treatment visits where metformin plus another drug was prescribed, the share of second-line therapy accounted for by dipeptidyl peptidase-4 (DPP-4) inhibitors decreased from 21.9% of treatment visits in 2015 to 20.8% of treatment visits in 2019; sulphonylurea use declined from 45.2% to 32.7%, use of SGLT2 inhibitors increased from 14.5% to 21.2% and use of GLP-1 receptor agonists increased from 9.8% to 18.2%.

CONCLUSIONS

Significant changes in the landscape of ambulatory care for diabetes have taken place during the past 6 years, including moderate declines in metformin monotherapy, moderate declines in second-line sulphonylurea use, and large increases in SGLT2 use. These changes underscore the dynamic nature of drug utilization for diabetes in the United States, and reflect the effects of emerging evidence, evolving clinical guidelines and evolving regulatory and payment policies.

Association of Serum Aldosterone and Plasma Renin Activity With Ambulatory Blood Pressure in African Americans: The Jackson Heart Study

BACKGROUND

The renin-angiotensin-aldosterone system (RAAS) is an important driver of blood pressure (BP), but the association of the RAAS with ambulatory BP (ABP) and ABP monitoring phenotypes among African Americans has not been assessed.

METHODS

ABP and ABP monitoring phenotypes were assessed in 912 Jackson Heart Study participants with aldosterone and plasma renin activity (PRA). Multivariable linear and logistic regression analyses were used to analyze the association of aldosterone and PRA with clinic, awake, and asleep systolic BP and diastolic BP (DBP) and ABP monitoring phenotypes, adjusting for important confounders.

RESULTS

The mean age of participants was 59±11 years and 69% were female. In fully adjusted models, lower log-PRA was associated with higher clinic, awake, and asleep systolic BP and DBP (all P<0.05). A higher log-aldosterone was associated with higher clinic, awake, and asleep DBP (all P<0.05). A 1-unit higher log-PRA was associated with lower odds of daytime hypertension (odds ratio [OR] 0.59 [95% CI, 0.49-0.71]), nocturnal hypertension (OR, 0.68 [95% CI, 0.58-0.79]), daytime and nocturnal hypertension (OR, 0.59 [95% CI, 0.48-0.71]), sustained hypertension (OR, 0.52 [95% CI, 0.39-0.70]), and masked hypertension (OR 0.75 [95% CI, 0.62-0.90]). A 1-unit higher log-aldosterone was associated with higher odds of nocturnal hypertension (OR, 1.38 [95% CI, 1.05-1.81]). Neither PRA nor aldosterone was associated with percent dipping, nondipping BP pattern, or white-coat hypertension. Patterns for aldosterone:renin ratio were similar to patterns for PRA.

CONCLUSIONS

Suppressed renin activity and higher aldosterone:renin ratios were associated with higher systolic BP and DBP in the office and during the awake and asleep periods as evidenced by ABP monitoring. Higher aldosterone levels were associated with higher DBP, but not systolic BP, in the clinic and during the awake and asleep periods. Further clinical investigation of novel and approved medications that target low renin physiology such as epithelial sodium channel inhibitors and mineralocorticoid receptor antagonists may be paramount in improving hypertension control in African Americans.

Use of Preventive Aspirin Among Older US Adults With and Without Diabetes

IMPORTANCE

The net benefit of aspirin for prevention of cardiovascular disease (CVD), particularly primary prevention, remains debated in people with and without diabetes. Recent studies suggest that the benefits of preventive aspirin may be outweighed by the potential for harm in older adults; therefore, it is important to monitor current aspirin use in order to minimize risk for future harm in the oldest segment of the population.

OBJECTIVE

To determine the prevalence of preventive aspirin use in older US adults with and without diabetes for both primary and secondary prevention by age, sex, and CVD risk category.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional analysis used nationally representative data from the National Health and Nutrition Examination Survey from 2011 to 2018. A total of 7103 individuals 60 years or older with and without diabetes completed a questionnaire on preventive aspirin use. Statistical analyses were performed from July 1, 2019, to April 1, 2021.

MAIN OUTCOMES AND MEASURES

Preventive aspirin use was defined as participants' self-reported use of low-dose aspirin therapy based on their physician's advice or their own decision.

RESULTS

A total of 7103 individuals (mean [SD] age, 69.6 [0.1] years; 45.2% men; 75.8% White participants) were evaluated. Overall, 61.7% of older US adults with diabetes vs 42.2% without diabetes used aspirin. Among people with diabetes, in multivariable logistic models adjusting for race, sex, education, CVD risk category, and body mass index, the likelihood of aspirin use in older vs younger age categories (reference: 60-69 years) did not differ. Among people without diabetes, aspirin use was significantly greater in older age categories vs the reference (model 3, 70-79 years, odds ratio [OR], 1.50; 95% CI, 1.23-1.83; model 3, ≥80 years, OR, 1.59; 95% CI, 1.24-2.04). An estimated 9.9 million US adults 70 years or older with or without diabetes reported taking aspirin for primary prevention. The likelihood of aspirin use for primary prevention in those at high vs low risk for CVD did not differ among older adults with diabetes (model 3, OR, 1.69; 95% CI, 0.65-4.39) but was significantly higher in those without diabetes (model 3, OR, 2.46; 95% CI, 1.63-3.71). Women vs men with diabetes were less likely to be using aspirin for primary prevention (model 3, OR, 0.63; 95% CI, 0.48-0.83).

CONCLUSIONS AND RELEVANCE

This cross-sectional study found that preventive aspirin use was higher among older adults with diabetes than in those without diabetes. Results suggest that 9.9 million older US adults who previously took aspirin for primary prevention would not be recommended for its continued use, particularly among those with diabetes.

The trans-ancestral genomic architecture of glycemic traits

Glycemic traits are used to diagnose and monitor type 2 diabetes and cardiometabolic health. To date, most genetic studies of glycemic traits have focused on individuals of European ancestry. Here we aggregated genome-wide association studies comprising up to 281,416 individuals without diabetes (30% non-European ancestry) for whom fasting glucose, 2-h glucose after an oral glucose challenge, glycated hemoglobin and fasting insulin data were available. Trans-ancestry and single-ancestry meta-analyses identified 242 loci (99 novel; P < 5 × 10-8), 80% of which had no significant evidence of between-ancestry heterogeneity. Analyses restricted to individuals of European ancestry with equivalent sample size would have led to 24 fewer new loci. Compared with single-ancestry analyses, equivalent-sized trans-ancestry fine-mapping reduced the number of estimated variants in 99% credible sets by a median of 37.5%. Genomic-feature, gene-expression and gene-set analyses revealed distinct biological signatures for each trait, highlighting different underlying biological pathways. Our results increase our understanding of diabetes pathophysiology by using trans-ancestry studies for improved power and resolution.

Determinants of mental health outcomes among people with and without diabetes during the COVID-19 outbreak in the Arab Gulf Region

AIMS

To determine the prevalence and factors associated with depression and anxiety among people with and without diabetes during the coronavirus disease 2019 (COVID-19) outbreak.

METHODS

A cross-sectional questionnaire-based study collecting demographic and mental health data from 2166 participants living in the Arab Gulf region (568 with diabetes, 1598 without diabetes). Depression and anxiety were assessed using the 9-item Patient Health Questionnaire and the 7-item Generalized Anxiety Disorder scale, respectively.

RESULTS

The prevalence of depression and anxiety symptoms were 61% and 45%, in people with diabetes (PWD) and 62% and 44%, respectively, in people without diabetes. PWD who have had their diabetes visit canceled by the clinic were more likely to report depression and anxiety symptoms than those without diabetes (odds ratio [95% confidence interval]: 1.37 [1.02, 1.84] and 1.37 [1.04, 1.80], for depression and anxiety; respectively). PWD who had no method of telecommunication with their health care providers (HCP) during the pandemic, PWD with A1C of ≥ 10%, women, employees (particularly HCPs), students, unmarried individuals, and those with lower income were more likely to report depression and/or anxiety symptoms (all P < 0.01). Fear of acquiring the coronavirus infection; running out of diabetes medications; or requiring hospitalization for hypoglycemia, hyperglycemia, or diabetic ketoacidosis; and lack of telecommunication with HCPs were all associated with significantly higher odds of having depression and anxiety symptoms among PWD.

CONCLUSIONS

The remarkably high prevalence of depression and anxiety symptoms during the COVID-19 pandemic, particularly among subgroups of PWD, calls for urgent public health policies to address mental health during the pandemic and reestablish health care access for PWD.

Adiposity Measures and Morning Serum Cortisol in African Americans: Jackson Heart Study

OBJECTIVE

Altered hormonal regulation, including cortisol, is a proposed mechanism linking adiposity to obesity-related disorders. We examined the association of anthropometric, adipokine, and body fat distribution measures of adiposity with morning serum cortisol in an African American (AA) cohort.

METHODS

We investigated the cross-sectional associations of adiposity measures (BMI, waist circumference, leptin, adiponectin, leptin:adiponectin ratio, subcutaneous and visceral adipose tissue) and liver attenuation with cortisol in the Jackson Heart Study. Linear regression models were used to analyze the association between exposures and cortisol. Models were adjusted for multiple covariates.

RESULTS

Among 4,211 participants, a 1-SD higher BMI and waist circumference were associated with a 3.92% and 3.05% lower cortisol, respectively. A 1-SD higher leptin and leptin:adiponectin ratio were associated with a 6.48% and 4.97% lower morning serum cortisol, respectively. A 1-SD higher subcutaneous adipose tissue was associated with a 4.97% lower cortisol (all P < 0.001). There were no associations of liver attenuation or visceral adipose tissue with cortisol.

CONCLUSIONS

Several measures of adiposity are associated with lower morning serum cortisol among AAs, with leptin having the greatest magnitude. Future studies examining the role of morning serum cortisol in the pathway from adiposity to cardiometabolic disease in AAs are warranted.

The Effects of Four Doses of Vitamin D Supplements on Falls in Older Adults : A Response-Adaptive, Randomized Clinical Trial

BACKGROUND

Vitamin D supplementation may prevent falls in older persons, but evidence is inconsistent, possibly because of dosage differences.

OBJECTIVE

To compare the effects of 4 doses of vitamin D₃ supplements on falls.

DESIGN

2-stage Bayesian, response-adaptive, randomized trial. (ClinicalTrials.gov: NCT02166333).

SETTING

2 community-based research units.

PARTICIPANTS

688 participants, aged 70 years and older, with elevated fall risk and a serum 25-hydroxyvitamin D [25-(OH)D] level of 25 to 72.5 nmol/L.

INTERVENTION

200 (control), 1000, 2000, or 4000 IU of vitamin D₃ per day. During the dose-finding stage, participants were randomly assigned to 1 of the 4 vitamin D₃ doses, and the best noncontrol dose for preventing falls was determined. After dose finding, participants previously assigned to receive noncontrol doses received the best dose, and new enrollees were randomly assigned to receive 200 IU/d or the best dose.

MEASUREMENTS

Time to first fall or death over 2 years (primary outcome).

RESULTS

During the dose-finding stage, the primary outcome rates were higher for the 2000- and 4000-IU/d doses than for the 1000-IU/d dose, which was selected as the best dose (posterior probability of being best, 0.90). In the confirmatory stage, event rates were not significantly different between participants with experience receiving the best dose (events and observation time limited to the period they were receiving 1000 IU/d; n = 308) and those randomly assigned to receive 200 IU/d (n = 339) (hazard ratio [HR], 0.94 [95% CI, 0.76 to 1.15]; P = 0.54). Analysis of falls with adverse outcomes suggested greater risk in the experience-with-best-dose group versus the 200-IU/d group (serious fall: HR, 1.87 [CI, 1.03 to 3.41]; fall with hospitalization: HR, 2.48 [CI, 1.13 to 5.46]).

LIMITATIONS

The control group received 200 IU of vitamin D₃ per day, not a placebo. Dose finding ended before the prespecified thresholds for dose suspension and dose selection were reached.

CONCLUSION

In older persons with elevated fall risk and low serum 25-(OH)D levels, vitamin D₃ supplementation at doses of 1000 IU/d or higher did not prevent falls compared with 200 IU/d. Several analyses raised safety concerns about vitamin D₃ doses of 1000 IU/d or higher.

PRIMARY FUNDING SOURCE

National Institute on Aging.

Principles and Issues for Physical Frailty Measurement and Its Clinical Application

INTRODUCTION

"Frailty" has attracted attention for its promise of identifying vulnerable older adults, hence its potential use to better tailor geriatric health care. There remains substantial controversy, however, regarding its nature and ascertainment. Recent years have seen a proliferation of frailty assessment methods. We argue that the development of frailty assessments should be grounded in "validation"-the process of substantiating that a measurement accurately and precisely measures what it intends, identify unresolved measurement issues, and highlight measurement-related considerations for clinical practice.

METHODS

Principles for validating frailty measures are elucidated. We follow principles-articulated, for example, by Borsboom-in which a construct must be clearly defined and then analyses undertaken to substantiate that a measurement accurately and precisely measures what it intends. Key elements are content validity, criterion validity, and construct validity, with an emphasis on the latter.

RESULTS

We illustrate the principles for a physical frailty phenotype construct.

CONCLUSIONS

Unresolved conceptual issues include the roles of intersecting concepts such as cognition, disease severity, and disability in frailty measurement, conceptualization of frailty as a state versus a continuum, and the potential need for dynamic measures and systems concepts in furthering understanding of frailty. Clinical considerations include needs to distinguish interventions designed to address frailty "symptoms" versus underlying physiology, improve "prefrailty" measures intended to screen individuals early in their frailty progression, address feasibility demands, and further visioning followed by rigorous efficacy research to address the landscape of potential uses of frailty assessment in clinical practice.

Dipeptidyl peptidase-4 inhibitors and cardiovascular events in patients with type 2 diabetes, without cardiovascular or renal disease

Background

Cardiovascular safety of dipeptidyl peptidase-IV inhibitors (DPP-4i) in patients without cardiovascular or renal disease, a majority of newly diagnosed patients with type 2 diabetes often excluded from clinical trials on this association, is poorly understood. Thus, we investigate the risk of major adverse cardiovascular events (MACE) associated with DPP-4i in low-risk patients with diabetes

Methods

Using a new-user retrospective cohort derived from IBM MarketScan Commercial Claims and Encounters (2010–2015), we identified patients aged 35–65 with type 2 diabetes, without cardiovascular or renal disease, initiating DPP-4i, sulfonylureas, or metformin. Primary composite outcome of time to first MACE was defined as the first of any of the following: myocardial infarction, cardiac arrest, coronary artery bypass graft, coronary angioplasty, heart failure, and stroke. Secondary outcomes were time to first heart failure, acute myocardial infarction, and stroke. We compared outcomes for DPP-4i versus sulfonylurea and DPP-4i versus metformin using propensity score weighted Cox proportional hazards, adjusting for demographics, baseline comorbidities, concomitant medications, and cumulative exposure.

Results

Of 445,701 individuals, 236,431 (53.0%) were male, median age was 51 (interquartile range: [44, 57]), 30,267 (6.79%) initiated DPP-4i, 52,138 (11.70%) initiated sulfonylureas, and 367,908 (82.55%) initiated metformin. After adjustment, DPP-4i was associated with lower risk of MACE than sulfonylurea (adjusted hazard ratio (aHR) = 0.87; 95% confidence interval (CI): 0.78–0.98), and similar risk to metformin (aHR = 1.07; 95% CI: 0.97–1.18). Risk for acute myocardial infarction (aHR = 0.70; 95% CI: 0.51–0.96), stroke (aHR = 0.57; 95% CI: 0.41–0.79), and heart failure (aHR = 0.57; 95% CI: 0.41–0.79) with DPP-4i was lower compared to sulfonylureas.

Conclusion

Our findings show that for this cohort of low-risk patients newly treated for type 2 diabetes, DPP-4i exhibited 13% lower risk for MACE compared to sulfonylureas and similar risk for MACE compared to metformin, suggesting DPP-4i is a low cardiovascular risk option for low-risk patients initiating antihyperglycemic treatment.

Mitochondrial DNA copy number and diabetes: the Atherosclerosis Risk in Communities (ARIC) study

INTRODUCTION

Mitochondrial DNA copy number (mtDNA-CN) is a measure of mitochondrial dysfunction and is associated with diabetes in experimental models. To explore the temporality of mitochondrial dysfunction and diabetes, we estimated the prevalent and incident association of mtDNA-CN and diabetes.

RESEARCH DESIGN AND METHODS

We assessed the associations of mtDNA-CN measured from buffy coat with prevalent and incident diabetes, stratified by race, in 8954 white and 2444 black participants in the Atherosclerosis Risk in Communities (ARIC) study, an observational cohort study. Follow-up for incident analyses was complete through visit 6, 2016.

RESULTS

Mean age at mtDNA-CN measurement was 57 years and 59% were female. Prevalence of diabetes at time of mtDNA-CN measurement was higher in blacks (563/2444, 23%) than whites (855/8954, 10%). The fully adjusted odds of prevalent diabetes for the 10th vs 90th percentile of mtDNA-CN was 1.05 (95% CI 0.74 to 1.49) among black and 1.49 (95% CI 1.20 to 1.85) among white participants. Over a median follow-up time of 19 years (Q1, Q3: 11, 24 years), we observed 617 incident diabetes cases among 1744 black and 2121 cases among 7713 white participants free of diabetes at baseline. The fully adjusted hazard of incident diabetes for the 10th vs 90th percentile of mtDNA-CN was 1.07 (95% CI 0.84 to 1.38) among black and 0.97 (95% CI 0.86 to 1.10) among white participants.

CONCLUSIONS

Lower mtDNA-CN in buffy coat was associated with prevalent diabetes in white but not black ARIC participants. Lower mtDNA-CN was not associated with incident diabetes over 20 years of follow-up in whites or blacks.

The Relationship of Lean Body Mass With Aging to the Development of Diabetes

CONTEXT

Older adults have the greatest burden of diabetes; however, the contribution of age-related muscle loss to its development remains unclear.

OBJECTIVE

We assessed the relationship of lean body mass with aging to incident diabetes in community-dwelling adults.

DESIGN AND SETTING

We studied participants in the Baltimore Longitudinal Study of Aging with median follow-up of 7 years (range 1-16). Cox proportional hazard models with age as the time scale were used. Time-dependent lean body mass measures were updated at each follow-up visit available.

PARTICIPANTS

Participants included 871 men and 984 women without diabetes who had  ≥ 1 assessment of body composition using dual x-ray absorptiometry.

MAIN OUTCOMES

Incident diabetes, defined as self-reported history and use of glucose-lowering medications; or fasting plasma glucose ≥ 126 mg/dL and 2-hour oral glucose tolerance test glucose ≥ 200 mg/dL either at the same visit or 2 consecutive visits.

RESULTS

The baseline mean [standard deviation] age was 58.9  [17.3] years. Men and women with a higher percentage of total lean body mass had lower fasting and 2-hour glucose levels, and less prediabetes (all P < 0.01). Among men, comparing highest versus lowest quartiles, percentage of total lean body mass (hazard ratio [HR],  0.46; 95% confidence interval, 0.22-0.97), percentage leg lean mass (HR, 0.38; 0.15-0.96), and lean-to-fat mass ratio (HR, 0.39; 0.17-0.89) were inversely associated with incident diabetes after accounting for race and attenuated after adjustment for height and weight. Conversely, absolute total lean body mass was positively associated with incident diabetes among women, with similar trends in men. No associations were observed with muscle strength or quality.

CONCLUSIONS

Relatively lower lean body mass with aging is associated with incident diabetes in men and partially related to anthropometrics, but not so in women.