Singh, Jasraj

BACKGROUND: Although diabetes is a known driver of heart failure with preserved ejection fraction, whether antecedent hyperinsulinemia drives preclinical diastolic dysfunction (DD) progression before overt hyperglycemia remains unknown. Therefore, we investigated whether elevated endogenous insulin and insulin resistance independently predict longitudinal DD progression and adverse cardiovascular outcomes. METHODS: In a community-based cohort study, we evaluated 1191 participants from the Olmsted County Heart Function Study (median age, 58.7 [interquartile range, 52.4–66.6 years]) who underwent echocardiography at baseline and after 4 years. Fasting insulin and homeostatic model assessment of insulin resistance were assessed. The primary end point was DD progression. Secondary outcomes (mortality, heart failure) were assessed in 2030 participants followed for a median of 10.97 (95% CI, 10.90–11.05) years for heart failure and a median of 18.1 (95% CI, 18.0–18.2) years for mortality. RESULTS: DD progression occurred in 7.5% of participants. Baseline fasting insulin and homeostatic model assessment of insulin resistance strongly predicted progression ( P <0.001). In multivariable analysis, every 1-SD increase in log-transformed insulin was associated with 65% increased odds of progression (odds ratio, 1.65 [95% CI, 1.33–2.07]; P <0.001), adjusting for age, creatinine, and NT-proBNP (N-terminal pro-B-type natriuretic peptide). Similar results were observed for homeostatic model assessment of insulin resistance (odds ratio, 1.66 [95% CI, 1.34–2.08]; P <0.001). In secondary analyses, elevated insulin independently predicted all-cause (hazard ratio, 1.11 per 1-SD [95% CI, 1.02–1.21]) and cardiovascular mortality (hazard ratio, 1.16 [95% CI, 1.02–1.33]). Homeostatic model assessment of insulin resistance was similarly predictive of all-cause (hazard ratio, 1.11 [95% CI, 1.03–1.20]) and cardiovascular mortality (hazard ratio, 1.16 [95% CI, 1.02–1.32]). CONCLUSIONS: Elevated endogenous insulin and insulin resistance are predictors of progressive DD and long-term mortality, even after accounting for body mass index. Metabolic dysregulation may drive myocardial stiffening before diabetes onset, identifying a potential early therapeutic window for heart failure with preserved ejection fraction prevention.

Background: Diabetic cardiomyopathy is a common complication of diabetes, which can progress to symptomatic heart failure. Current conventional medical therapy does not reverse the deleterious features of diabetic cardiomyopathy. The natriuretic peptide-cGMP system has been proven to provide a cardioprotective role in diabetic rats. Therefore, we developed CRRL094, a n bispecific peptide that simultaneously activates the natriuretic peptide system and glucagon-like peptide-1 (GLP-1) receptor. In this study, we aimed to characterize the cardioprotective role of CRRL094 and elucidate its downstream molecular mechanisms. Methods: In vitro, human cardiomyocytes (HCMs) were pretreated with PBS or CRRL094 (5 µM) for 6 hours, then exposed to high glucose treatment (HGT, 25 mM) for 48 hours. HCM hypertrophy was determined by assessing mRNA levels of hypertrophic gene markers (NPPA and NPPB) using real-time PCR. Lipid droplet staining was performed using BODIPY 493/503 dye and fluorescence images were analyzed. The protein levels of CIDEC (lipid droplet-related gene) and phosphorylation-AMPK and total AMPK (a key regulator of lipid metabolism) were analyzed by Western blot. In vivo, a type 2 diabetes (DM2) rat model was established by low-dose intraperitoneal Streptozotocin (STZ) injection and a high-fat diet in Wistar rats (male, 4- to 6-week-old). Diabetes was confirmed by fasting blood glucose > 350 mg/dL. Rats were then allocated to two groups: saline-treated controls (n=6) or CRRL094-treated (30 pmol/kg/min; n=6), with treatment delivered via osmotic pumps for 28 days. Heart tissues were collected and analyzed. Results: HGT in HCMs significantly increased the mRNA levels of NPPA and NPPB, whereas CRRL094 significantly attenuated markers of hypertrophy. Further, HGT increased lipid accumulation in HCMs, which was decreased with CRRL094 treatment. Moreover, CRRL094 increased p-AMPK protein levels and decreased CIDEC protein levels in HCMs under HGT. In a DM2 rat model, chronic CRRL094 therapy was associated with suppression of NPPA and NPPB, downregulation of CIDEC, and upregulation of p-AMPK expression in the heart tissue. Conclusion: CRRL094 protects against HGT-induced hypertrophy and inhibits lipid accumulation through regulating the AMPK/CIDEC pathway in vitro and in vivo . These findings support CRRL094 as a novel therapeutic candidate to prevent diabetic cardiomyopathy.

Introduction: Diabetes mellitus (DM) is strongly associated with metabolic and cardiorenal derangements. Natriuretic peptides (NPs), and glucagon-like peptide 1 receptor agonists (GLP-1 RA) have well-established cardiometabolic and cardiorenal protective effects. We developed a novel bispecific biologic, CRRL 101, which agonizes guanylyl cyclase A (GCA) NP receptors and GLP-1 receptors. In this study, we sought to evaluate the in vitro effects and in vivo impact of CRRL 101 in a DM rat model. Methods: In vitro experiments evaluated the impact of CRRL 101 treatment of GCA receptor transfected human embryonic kidney (HEK) cells and INS-1 rat pancreatic beta cells. In vivo experiments were conducted by inducing DM in Wistar rats (male, 6-8-week-old) by intraperitoneal Streptozotocin (STZ) injection (65 mg/kg). One week after STZ injection, DM was confirmed (fasting blood glucose > 350 mg/dL). Rats were then divided into 3 groups: saline control (n=6), 1 pmol/kg/min CRRL-101 (“1pmol” n= 4), and 10 pmol/kg/min CRRL-101 (“10 pmol” n=5). Treatment was infused for 120 min after which rat blood and urine were collected. Data were analyzed using GraphPad Prism 10.0.0. Results: In vitro, there was a marked increase in cyclic GMP (cGMP) levels (pmol/mL) in HEK treated with 10 -6 M CRRL 101 (mean difference ± SEM:1.603 ± 0.29 p = 0.0048). In INS-1 cells treated with CRRL 101 at 10 -6 M in a 20 mM glucose medium, cAMP levels (pmol/mL) markedly increased (16.7 ± 1.47 vs 23.19 ± 1.51 p=0.0036) and insulin levels (ng/mL) doubled (4.4 ng/mL ± 0.44 vs 9.5 ng/mL ± 0.34 in 20 mM glucose p < 0.0001). Similar increases were observed at lower doses (10 -7 M, 10 -8 M) of CRRL 101. In vivo , after 120 minutes of treatment, mean plasma cGMP levels were 6.5x greater in both groups (mean difference± SEM) (1pmol: 38.89 ± 7.93, p = 0.016; 10pmol: 39.40 ± 4.84 p=0.001). Plasma insulin (ng/mL) more than doubled with both doses (1pmol: 0.39 ± 0.148, p = 0.039; 10 pmol: 0.198 ± 0.051, p = 0.004) with no significant increase with placebo ( 0.03 ± 0.08, p = 0.67). Rate of natriuresis (mEq/min) more than doubled with peptide administration vs placebo (1 pmol: 0.36 ± 0.093 p = 0.014; 10 pmol: 0.38 ± 0.13, p = 0.034). Conclusions: Our novel bispecific biologic, CRRL 101, activates GC-A, increasing plasma cGMP and inducing natriuresis, and stimulates GLP-1R, raising cAMP and plasma insulin. Chronic administration studies to eludicate its therapeutic efficacy are warranted.

Erdheim–Chester disease (ECD) is a rare non-Langerhans cell histiocytosis characterised by multiorgan pathological histiocytic infiltration. Cardiac involvement occurs in 40–75% of patients and increases mortality. A 55-year-old woman with chest pain and dyspnoea was found to have an interatrial septal mass and aortitis suspicious for ECD without other organ involvement. After two inadequate transcatheter interatrial biopsies were obtained using ultrasound guidance alone, diagnostic samples were successfully obtained using intraprocedural frozen section examination. The patient started genotype-targeted treatment with good response. Biopsy confirmation of ECD is required to guide treatment; however, cardiac biopsies are uncommonly performed when other organs are affected. Our unique case of isolated cardiovascular involvement highlights how frozen sectioning with multimodal intraprocedural imaging guidance can improve diagnostic yield of endomyocardial biopsies. It also highlights how diagnosis of rare conditions requires careful multidisciplinary evaluation of affected organs, procedural risk and diagnostic yield. The use of frozen sectioning can improve diagnostic yield of endomyocardial biopsies.

Abstract Aims Define the relationship between N‐terminal atrial natriuretic peptide (NT‐ANP) levels and incident metabolic syndrome and type 2 diabetes mellitus (‘metabolic disease’) in healthy adults and develop a risk prediction score. Materials and Methods Retrospective cohort study of Olmsted County Heart Function Study participants, a random sampling of county residents aged 45 years and older ( n = 2042). Clinical data were collected during enrolment between 1997 and 2000 and upon follow‐up 4 years later. Outcomes were followed for 8 years. We studied 715 subjects without metabolic disease at enrolment who completed follow‐up, assessing incident metabolic disease as the primary outcome. Youden's index was used to identify optimal cut‐points and develop the risk score. Results Upon multivariate analysis adjusting for age gender, HDL and triglycerides, higher baseline serum NT‐ANP levels were associated with a lower risk of metabolic disease (OR: 0.65, CI 0.49–0.85, p = 0.002). Higher baseline serum insulin and aldosterone levels were associated with higher risk of incident metabolic disease (OR: 2.04, CI 1.57–2.65, p < 0.001; OR: 1.43, CI 1.14–1.81, p = 0.002, respectively). Baseline serum NT‐ANP < 3337 pg/mL was 96.6% sensitive for future development of metabolic disease. A weighted score including all three biomarkers was 78.6% sensitive and 77.3% specific. Conclusions In healthy adults aged 45 years or older, higher baseline NT‐ANP levels are associated with a lower four‐year risk of developing metabolic disease. Serum NT‐ANP levels are a sensitive biomarker of future risk of metabolic disease and have screening utility when combined with insulin and aldosterone levels into a composite score.