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ContextDiabetes or hyperglycemia at admission are established risk factors for adverse outcomes during hospitalization for COVID-19, but the impact of prior glycemic control is not clear.ObjectiveWe aimed to examine the associations between admission variables, including glycemic gap, and adverse clinical outcomes in patients hospitalized with COVID-19 infection.MethodsWe examined the relationship between clinical predictors, including acute and chronic glycemia, and clinical outcomes, including intensive care unit (ICU) admission, mechanical ventilation (MV), and mortality among 1786 individuals with diabetes or hyperglycemia (glucose > 10 mmol/L twice in 24 hours) who were admitted from March 2020 through February 2021 with COVID-19 infection at 5 university hospitals in the eastern United States.ResultsThe cohort was 51.3% male, 53.3% White, 18.8% Black, 29.0% Hispanic, with age = 65.6 ± 14.4 years, BMI = 31.5 ± 7.9 kg/m2, glucose = 12.0 ± 7.5 mmol/L [216 ± 135 mg/dL], and HbA1c = 8.07% ± 2.25%. During hospitalization, 38.9% were admitted to the ICU, 22.9% received MV, and 10.6% died. Age (P < 0.001) and admission glucose (P = 0.014) but not HbA1c were associated with increased risk of mortality. Glycemic gap, defined as admission glucose minus estimated average glucose based on HbA1c, was a stronger predictor of mortality than either admission glucose or HbA1c alone (OR = 1.040 [95% CI: 1.019, 1.061] per mmol/L, P < 0.001). In an adjusted multivariable model, glycemic gap, age, BMI, and diabetic ketoacidosis on admission were associated with increased mortality, while higher estimated glomerular filtration rate (eGFR) and use of any diabetes medication were associated with lower mortality (P < 0.001).ConclusionRelative hyperglycemia, as measured by the admission glycemic gap, is an important marker of mortality risk in COVID-19.

Context: Aldosterone production is associated with insulin resistance in obese and hypertensive subjects. However, its effect on insulin sensitivity in healthy subjects is not clear. Objective: The objective of this study was to test the hypothesis that increased aldosterone production is associated with lower insulin sensitivity in healthy subjects. Design: This is an analysis of data previously collected during studies conducted as part of the International Hypertensive Pathotype Consortium. Participants and Interventions: Eighty-four subjects free of any medical or psychiatric illness were included in this study. They were studied after 7 d of a standardized high-sodium diet confirmed by 24-h urine sodium above 200 mEq. Insulin sensitivity index (ISI) was calculated after a 75-g oral glucose load with glucose and insulin measurements at 0, 30, 60, and 120 min. Serum aldosterone levels were measured after 45 min of angiotensin II (3 ng/kg/min) infusion. Results: There were significant negative correlations between ISI and age, body mass index (BMI), diastolic blood pressure, and angiotensin II-stimulated aldosterone level (P < 0.01). On multivariate regression analysis, stimulated aldosterone level was an independent predictor of ISI after adjusting for age, BMI, and diastolic blood pressure. Stimulated aldosterone level predicted 8% of the variance in ISI (P = 0.003) with age, BMI, and diastolic blood pressure together predicting 23% of the variance in ISI. Thus, the final regression model predicted 31% of the variance in ISI (P < 0.0001). Conclusions: Aldosterone production is associated with insulin resistance in normotensive healthy subjects independent of traditional risk factors.

Context: The mechanisms underlying obesity-mediated cardiovascular disease are not fully understood. Aldosterone and insulin resistance both are associated with obesity and cardiovascular disease. Objectives: The objectives of this study were to test the hypotheses that aldosterone production is elevated and associated with insulin resistance in overweight adults on a high-sodium diet. Participants/Interventions: Healthy normotensive adults were categorized as lean body mass index (BMI) less than 25 kg/m2 (n = 63) or overweight BMI 25 kg/m2 or greater (n = 57). After 7 d of a high-sodium diet, participants fasted overnight and remained supine throughout hemodynamic and laboratory assessments and angiotensin II (AngII) stimulation. Results: The overweight group, compared with the lean group, had higher 24-h urinary aldosterone (9.0 ± 0.8 vs. 6.6 ± 0.5 μg per 24 h; P = 0.003) and higher AngII-stimulated serum aldosterone (11.4 ± 1.0 vs. 9.0 ± 0.6 ng/dl; P = 0.04). There were no differences in 24-h urinary cortisol or sodium or supine measurements of plasma renin activity, serum aldosterone, or serum potassium. The homeostasis model assessment of insulin resistance was predicted by urinary aldosterone excretion (r = 0.32, P = 0.03) and serum aldosterone response to AngII stimulation (r = 0.28, P = 0.02) independent of age and BMI. Conclusion: Urinary aldosterone excretion and AngII-stimulated aldosterone are increased in overweight, compared with lean, normotensive adults. The correlation of these measures of aldosterone production with insulin resistance suggests a potential role for aldosterone in the pathophysiology of obesity-mediated insulin resistance.

In view of the pro-oxidant and proinflammatory effects of angiotensin II, we have tested the hypothesis that valsartan, an angiotensin receptor blocker, may exert a suppressive action on reactive oxygen species (ROS) generation, nuclear factor kappa B (NF-kappa B) in mononuclear cells. Four groups of eight normal subjects were given 1) 160 mg daily of valsartan, 2) 80 mg daily of simvastatin, 3) 40 mg quinapril, or 4) no treatment. Fasting blood samples were obtained before treatment and at d 1, 8, and 14 (7 d after the cessation of the drug). After valsartan, ROS generation by polymorphonuclear cells and mononuclear cells fell significantly by more than 40% (P0.01). NF-kappa B binding activity and the expression of total cellular p65, a protein component of NF-kappa B, fell significantly (P0.01). The expression of inhibitor kappa B (I kappa B) increased significantly (P0.05). Plasma C-reactive protein (CRP) concentration fell significantly (P0.01). All indices, except I kappa B, reverted toward baseline, 7 d after the cessation of the drug. I kappa B persisted in an elevated state. Neither quinapril nor simvastatin given for 7 d produced a suppression of ROS generation, intranuclear NF-kappa B, p65, or CRP, and these two agents did not alter cellular I kappa B either. The untreated controls also did not demonstrate a change in their ROS generation or NF-kappa B binding activity or plasma CRP concentration. We conclude that valsartan at a modest dose exerts a profound and rapid ROS and inflammation-suppressive effect that may be relevant to its potential beneficial effects in atherosclerosis, diabetes, and congestive cardiac failure. In contrast, quinapril and simvastatin produced no similar effect over the period of 1 wk. Our observations may also have implications to clinical situations in which a rapid antiinflammatory effect is required.

We have recently demonstrated that troglitazone exerts an anti-inflammatory effect in the insulin resistant obese in vivo in parallel with its insulin-sensitizing effect. Because these effects are thought to be mediated through peroxisome proliferator-activated receptors α and γ (PPARα and PPARγ), we have now examined the possibility that troglitazone may modulate the expression of PPARα and PPARγ. Seven obese hyperinsulinemic subjects were administered 400 mg troglitazone daily for 4 weeks. Fasting blood samples were obtained before and during troglitazone therapy at 1, 2, and 4 weeks. Fasting insulin concentrations fell at week 1 and persisted at lower levels till 4 weeks. PPARγ expression fell significantly at week 1 and fell further at weeks 2 and 4. In contrast, PPARα expression increased significantly at week 2 and further at week 4. 9- and 13-hydroxyoctadecanoic acid, products of linoleic acid peroxidation and agonists of PPARγ, decreased during troglitazone therapy. We conclude that troglitazone, ...

It has been shown recently that troglitazone exerts an anti-inflammatory effect, in vitro, and in experimental animals. To test these properties in humans, we investigated the effect of troglitazone on the proinflammatory transcription factor nuclear factor-κB and its inhibitory protein IκB in mononuclear cells (MNC) and plasma soluble intracellular adhesion molecule-1, monocyte chemoattractant protein-1, plasminogen activator inhibitor-1, and C-reactive protein. We also examined the effect of troglitazone on reactive oxygen species generation, p47phox subunit expression, 9-hydroxyoctadecadienoic acid (9-HODE), 13-HODE, o-tyrosine, and m-tyrosine in obese patients with type 2 diabetes. Seven obese patients with type 2 diabetes were treated with troglitazone (400 mg/day) for 4 weeks. Blood samples were obtained at weekly intervals. Nuclear factor-κB binding activity in MNC nuclear extracts was significantly inhibited after troglitazone treatment at week 1 and continued to be inhibited up to week 4. On the ...

Since glucose intake acutely increases reactive oxygen species (ROS) generation by polymorphonuclear leucocytes (PMN) and mononuclear cells (MNC), we have now investigated whether a fast over a period of 48h reduces ROS generation by these cells. Eight normal subjects were fasted for 48h. Blood samples were obtained at 0, 24h and 48h. ROS generation by PMN fell significantly at 24h (66.1 ± 19.5% of basal) and further at 48h (45.9 ± 23.0 % of basal; p < 0.001). ROS generation by MNC fell to 62.4 ± 16.5% at 24h and by 48.4 ± 16.5% (p < 0.001) by 48h. The level of p47phox subunit, an index of NADPH oxidase, the enzyme converting molecular oxygen to superoxide (O˙2−) radical, also fell in parallel. Plasma o-tyrosine/phenylalanine ratio fell significantly from 0.326 ± 0.053 mmol/mol to 0.303 ± 0.055 mmol/mol at 48h and m-tyrosine/phenylalanine ratio fell from 0.363 ± 0.063 mmol/mol to 0.340 ± 0.064 mmol/mol (p < 0.05). Thus, a 48h fast may reduce ROS generation, total oxidative load and oxidative dama...

Increased reactive oxygen species generation by the leukocytes of the obese may be responsible for increased oxidative injury to lipids and proteins and, hence, atherosclerosis. We have investigated whether reactive oxygen species generation by leukocytes and other indexes of oxidative damage in the body fall with short-term dietary restriction and weight loss. Nine nondiabetic obese subjects (body mass index, 32.5-64.4 kg/m(2)), not taking any antioxidants, were put on a 1000-Cal diet. Fasting blood samples were taken at 0, 1, 2, 3, and 4 weeks and at 12 weeks after the cessation of dietary restriction. Blood samples were also obtained at 1 and 2 h after administration of 75 g oral glucose at 0 and 4 weeks. Mononuclear cells (MNC) and polymorphonuclear leukocytes (PMN) were isolated, and reactive oxygen species generation was measured. Plasma concentrations of thiobarbituric acid-reactive species (TBARS), 13-hydroxyoctadecadienoic acid (13-HODE), 9-hydroxyoctadecadienoic acid (9-HODE), carbonylated proteins, o-tyrosine, and m-tyrosine as indexes of oxidative damage to lipids, proteins and amino acids, respectively, were measured. Antioxidant vitamins were measured as indexes of antioxidant reserves. Plasma tumor necrosis factor-alpha concentrations were also measured. Mean weight loss was 2.4 +/- 0.6 kg at week 1, 2.5 +/- 1.7 kg at week 2, 3.9 +/- 0.8 kg at week 3, and 4.5 +/- 2.8 kg at week 4 (P < 0.05). Reactive oxygen species generation by PMN fell from 236.4 +/- 95.8 to 150.9 +/- 69.0, 125.9 +/- 24.3, 96.0 +/- 39.9, and 103.1 +/- 35.7 mV at weeks 1, 2, 3, and 4, respectively (P < 0.001). It increased 3 months after the cessation of dietary restriction to 270.0 +/- 274.3 mV. Reactive oxygen species generation by MNC fell from 187.8 +/- 75.0 to 101.7 +/- 64.5, 86.9 +/- 42.8, 63.8 +/- 14.3, and 75.1 +/- 32.2 mV and increased thereafter to 302.0 +/- 175.5 mV at 1, 2, 3, 4, and 16 weeks, respectively (P < 0.005). Reactive oxygen species generation by PMN and MNC increased in response to glucose; the relative increase was greater at 4 weeks than that at week 0 due to a fall in the basal levels of reactive oxygen species generation. Consistent with the fall in reactive oxygen species generation, there was a reduction in plasma TBARS from 1.68 +/- 0.17 micromol/L at week 0 to 1.47 micromol/L at 4 weeks (P < 0.05). The 13-HODE to linoleic acid ratio fell from a baseline of 100% to 56.4 +/- 36.1% at 4 weeks (P < 0.05), and the 9-HODE to linoleic acid ratio fell from a baseline of 100% to 60.5 +/- 37.7% at 4 weeks (P < 0.05). Carbonylated proteins fell from 1.39 +/- 0.27 microgram/mg protein at week 0 to 1.17 +/- 0.12 microgram/mg protein at week 4 (P < 0.05); o-tyrosine fell from 0.42 +/- 0.03 mmol/mol phenylalanine at week 0 to 0.36 +/- 0.02 mmol/mol phenylalanine at 4 weeks (P < 0.005), and m-tyrosine fell from 0.45 +/- 0.04 mmol/mol phenylalanine at week 0 to 0.40 +/- 0.03 mmol/mol phenylalanine at 4 weeks (P < 0.05). The basal concentrations of TBARS, 9-HODE, 13-HODE, carbonylated proteins, o-tyrosine, and m-tyrosine in the obese were significantly greater than those in normal subjects. On the other hand, tumor necrosis factor-alpha concentrations did not change during this 4-week period, nor was there any change in antioxidant vitamins. This is the first demonstration of 1) an increase in reactive oxygen species-induced damage in lipids, proteins, and amino acids in the obese compared with normal subjects; and 2) a decrease in reactive oxygen species generation by leukocytes and oxidative damage to lipids, proteins, and amino acids after dietary restriction and weight loss in the obese over a short period.

Diabetes mellitus is associated with increased ROS generation, oxidative injury and obesity. To elucidate the relationship between nutrition and ROS generation, we have investigated the effect of glucose challenge on ROS generation by leucocytes, p47phox protein, a key protein in the enzyme NADPH oxidase and alpha-tocopherol levels. Blood samples were drawn from 14 normal subjects prior to, at 1, 2 and 3 h following ingestion of 75 g glucose. ROS generation by polymorphonuclear leucocytes (PMNL) and mononuclear cells (MNC) increased to a peak of 244 +/- 42% and 233 +/- 34% of the basal respectively at 2h. The levels of p47phox in MNC homogenates increased significantly at 2 h and 3 h after glucose intake. alpha-Tocopherol levels decreased significantly at 1 h, 2 h and 3 h. We conclude that glucose intake stimulates ROS generation and p417phox of NADPH oxidase; increases oxidative load and causes a fall in alpha-tocopherol concentration.

In view of the fact that glucocorticoids have an immunosuppressive effect and the fact that interleukin-10 (IL-10) is inhibitory to T helper cell function, we have now investigated the effect of hydrocortisone on plasma IL-10 concentrations. Seven normal subjects were injected with 100 mg hydrocortisone intravenously between 8 and 9:00 a.m. Sequential blood samples were obtained prior to and 1, 2, 4, 8 and 24 h after the injection. Plasma IL-10 concentrations increased significantly and consistently following the injection in all subjects. The peak increase of IL-10 occurred at 4 h and the restoration to baseline by 8 h. The sequential values were (mean+/-SD): 3.0+/-1.3 pg/ml at 2 h, 9+/-4.2 pg/ml at 4 h, 3.7+/-1.8 pg/ml at 8 h and 3.7+/-1.4 pg/ml at 24 h. The magnitude of increase was 436% of the basal at peak effect. This effect of hydrocortisone (and possibly other glucocorticoids) may contribute to the immunosuppressive effect of this drug. IL-10 may also be potentially useful in the assessment of Cushing's Syndrome as a marker of end organ effect of glucocorticoids.