Plasma Sphingolipid Profile of Healthy Black and White Adults Differs Based on Their Parental History of Type 2 Diabetes

CONTEXT

Ceramides and sphingolipids have been linked to type 2 diabetes (T2D). The Ceramides and Sphingolipids as Predictors of Incident Dysglycemia (CASPID) study is designed to determine the association of plasma sphingolipids with the pathophysiology of human T2D.

OBJECTIVE

A comparison of plasma sphingolipids profiles in Black and White adults with (FH+) and without (FH-) family history of T2D.

DESIGN

We recruited 100 Black and White FH- (54 Black, 46 White) and 140 FH+ (75 Black, 65 White) adults. Fasting plasma levels of 58 sphingolipid species, including 18 each from 3 major classes (ceramides, monohexosylceramides, and sphingomyelins, all with 18:1 sphingoid base) and 4 long-chain sphingoid base-containing species, were measured by liquid chromatography/mass spectrometry.

RESULTS

Sphingomyelin was the most abundant sphingolipid in plasma (89% in FH-), and was significantly elevated in FH+ subjects (93%). Ceramides and monohexosylceramides comprised 5% and 6% of total sphingolipids in the plasma of FH- subjects, and were reduced significantly in FH+ subjects (3% and 4%, respectively). In FH+ subjects, most ceramide and monohexosylceramide species were decreased but sphingomyelin species were increased. The level of C18:1 species of all 3 classes was elevated in FH+ subjects.

CONCLUSION

Elevated levels of sphingomyelin, the major sphingolipids of plasma, and oleic acid-containing sphingolipids in healthy FH+ subjects compared with healthy FH- subjects may reflect heritable elements linking sphingolipids and the development of T2D.

Glycemic Response to Oral Dexamethasone Predicts Incident Prediabetes in Normoglycemic Subjects With Parental Diabetes

Background

Prediabetes, an often unrecognized precursor of type 2 diabetes (T2DM), is associated with cardiometabolic complications. Here, we investigated the utility of dexamethasone challenge in predicting incident prediabetes among normoglycemic subjects with parental T2DM enrolled in the prospective Pathobiology of Prediabetes in a Biracial Cohort study.

Design and Methods

After documenting normoglycemic status with an oral glucose tolerance test (OGTT), participants ingested dexamethasone (2 mg) at 10:00 pm, and fasting plasma glucose (FPG-Dex) and cortisol were measured at 8:00 am the next day. Subjects were followed quarterly for 5 years, the primary outcome being incident prediabetes. Serial assessments included body composition, blood chemistry, OGTT, insulin sensitivity, and secretion.

Results

We analyzed data from 190 participants (107 Black, 83 white; mean age 44.7 ± 10.0 years; body mass index [BMI] 29.8 ± 6.8 kg/m²; fasting plasma glucose [FPG] 90.9 ± 5.7 mg/dL). Following dexamethasone ingestion, plasma cortisol was < 5 µg/dL; FPG-Dex levels displayed marked variability (81-145 mg/dL) as did delta FPG (–7 to +48 mg/dL). During 5 years of follow-up, 58 of 190 subjects (30.5%) progressed to prediabetes. FPG-Dex (116.8 ± 10.9 vs 106.9 ± 10.8 mg/dL, P < 0.0001) and delta FPG (23.4 ± 10.1 vs 17.0 ± 10.2 mg/dL, P < 0.0001) were higher in progressors than nonprogressors. FPG-Dex (P = 0.007) was an independent predictor of incident prediabetes in a multivariate model that included age, race, gender, BMI, waist circumference, FPG, insulin sensitivity, and secretion. In further analyses, an FPG-Dex level ≥ 107 mg/dL predicted incident prediabetes with 88% sensitivity and 49% specificity.

Conclusions

The glycemic response to dexamethasone significantly predicted incident prediabetes among offspring of parents with T2DM, and may be a tool for uncovering latent risk of dysglycemia.

Multi-year reproducibility of hyperinsulinemic euglycemic clamp-derived insulin sensitivity in free-living adults: Association with incident prediabetes in the POP-ABC study

OBJECTIVE

The hyperinsulinemic euglycemic clamp (HEC) is the "gold standard" for measuring insulin sensitivity (Si-clamp). Here, we determined the reproducibility of serial HEC data in healthy subjects.

RESEARCH DESIGN AND METHODS

The Pathobiology of Prediabetes in A Biracial Cohort study assessed incident prediabetes in healthy African Americans (AA) and European Americans (EA) with parental type 2 diabetes mellitus during 5.5 years of follow-up. Assessments included anthropometry, OGTT, and HEC. Ninety subjects (44 AA, 46 EA) who underwent Year-1HEC consented to Year-3 HEC. We calculated coefficients of variation (CVs), 95% limits of agreement, and repeatability coefficients for Year-1 and Year-3 data, and assessed the association of change in Si-clamp with incident prediabetes.

RESULTS

The mean (SD) baseline age was 47.5 ± 8.13y, body mass index was 30.4 ± 9.16 kg/m², fasting plasma glucose was 93.7 ± 7.82 mg/dL and 2-hrPG was 126 ± 26.8 mg/dL. Si-clamp (umol/kg/min·pmol/L^-1) was 0.071 ± 0.04 in Year 1 and 0.067 ± 0.04 in Year 3 (P = 0.22). Year 1 and Year 3 values were strongly correlated (r = 0.81, P < 0.0001); the CV was 13.6% and repeatability coefficient was ±0.025. Intrasubject differences in serial Si-clamp were less than the repeatability coefficients and within the 95% limits of agreement. After 5.5 years of follow-up, 40 subjects progressed to prediabetes and 50 were nonprogressors. The change in Si-clamp was greater in progressors than nonprogressors (-10% vs. -2.5%, P = 0.02).

CONCLUSIONS

The HEC is reproducible over ~2 years in free-living individuals, with a temporal decline in Si-clamp that predicts prediabetes risk.

History of Cardiovascular Disease, Intensive Lifestyle Intervention, and Cardiovascular Outcomes in the Look AHEAD Trial

OBJECTIVE

To examine the effects of an intensive lifestyle intervention (ILI) on cardiovascular disease (CVD), the Action for Health in Diabetes (Look AHEAD) trial randomized 5,145 participants with type 2 diabetes and overweight/obesity to a ILI or diabetes support and education. Although the primary outcome did not differ between the groups, there was suggestive evidence of heterogeneity for prespecified baseline CVD history subgroups (interaction P = 0.063). Event rates were higher in the ILI group among those with a CVD history (hazard ratio 1.13 [95% CI: 0.90-1.41]) and lower among those without CVD (hazard ratio 0.86 [95% CI: 0.72-1.02]).

METHODS

This study conducted post hoc analyses of the rates of the primary composite outcome and components, adjudicated cardiovascular death, nonfatal myocardial infarction (MI), stroke, and hospitalization for angina, as well as three secondary composite cardiovascular outcomes.

RESULTS

Interaction P values for the primary and two secondary composites were similar (0.060-0.064). Of components, the interaction was significant for nonfatal MI (P = 0.035). This interaction was not due to confounding by baseline variables, different intervention responses for weight loss and physical fitness, or hypoglycemic events. In those with a CVD history, statin use was high and similar by group. In those without a CVD history, low-density lipoprotein cholesterol levels were higher (P = 0.003) and statin use was lower (P ≤ 0.001) in the ILI group.

CONCLUSIONS

Intervention response heterogeneity was significant for nonfatal MI. Response heterogeneity may need consideration in a CVD-outcome trial design.

MON-138 Why Is My Thigh Hurting so Much?: A Rare Case of Diabetic Myonecrosis

Background: Diabetic myonecrosis is a rare complication of long-standing, poorly controlled Type I and II Diabetes mellitus. It classically presents with sudden onset of pain and swelling of involved muscle, most often in lower extremities, which can mimic DVT. Clinical Case: A 32-year old lady with Insulin dependent type 2 diabetes mellitus since age 14, ESRD on peritoneal dialysis, came in to our hospital with worsening right thigh swelling and pain of 3 days duration. On physical exam, her vital signs were stable, and she had diffuse swelling in her right thigh without any erythema, with prominent tenderness on medial aspect of the thigh. Right thigh measured 22 inches circumferentially at midpoint, which is 17 cm from inguinal region, while her left thigh measured 18 inches circumferentially at midpoint. On admission, she had an elevated white count of 15,100, and creatinine kinase was normal. Her hemoglobin A1C was 7.2% in the setting of anemia of ESRD, where her hemoglobin was 8.5g/dL. Lower extremity venous doppler was negative for DVT. MRI of right lower extremity showed diffuse nonspecific polymyositis throughout proximal right thigh, small areas of decreased enhancement in vastus medialis and lateralis, and stated that in the setting of diabetes, evolving diabetic muscle infarctions are to be strongly considered. Infectious Disease saw the patient and concluded that there was no evidence of infection. Patient was diagnosed with Diabetic myonecrosis and was managed conservatively including with rest, analgesia, and aggressive glycemic control. During her 1-month follow-up visit, uniform swelling of right thigh decreased to 19.5 inches from 22 inches circumferentially at midpoint, and her right thigh tenderness has resolved. Conclusion: Diabetic myonecrosis should be suspected in any patient with Diabetes who presents with acute muscular pain and swelling, especially in the lower extremities. MRI is the modality of choice to confirm clinical diagnosis. Muscle biopsy can provide definitive diagnosis but is not currently recommended due to the risk of procedure-associated complications and prolonged recovery secondary to poor wound healing. Treatment consists of rest, analgesia, and rigorous glycemic control. Reference: (1) Horton WB, Taylor JS, Ragland TJ. Diabetic muscle infarction: a systematic review. BMJ Open Diabetes Research and Care 2015

Parental History of Type 2 Diabetes Abrogates Ethnic Disparities in Key Glucoregulatory Indices

CONTEXT

There are ethnic differences in glucoregulation and prevalence of type 2 diabetes, but studies on the role of genetics in modifying ethnic effects in normoglycemic African-Americans and Caucasians are limited. Therefore, we investigated glucoregulation in normoglycemic African-Americans and Caucasians with or without parental diabetes.

DESIGN

Fifty subjects with parental diabetes (from the Pathobiology of Prediabetes in a Biracial Cohort Study) and 50 subjects without parental diabetes were matched in age, sex, ethnicity, and body mass index (BMI). Subjects underwent a 75-g oral glucose tolerance test (OGTT), physical examination, anthropometry, biochemistries, indirect calorimetry and assessment of body composition, insulin sensitivity by euglycemic clamp (Si-clamp), and β-cell function by Disposition index.

RESULTS

The mean age was 40.5 ± 11.6 years, BMI 28.7 ± 5.9 kg/m2, fasting plasma glucose 90.2 ± 5.9 mg/dL, and 2-hour postglucose 120.0 ± 26.8 mg/dL. Offspring with parental diabetes showed higher glycemic excursion during OGTT-area under the curve-glucose (16,005.6 ± 2324.7 vs 14,973.8 ± 1819.9, P < 0.005), lower Si-clamp (0.132 ± 0.068 vs 0.162 ± 0.081 µmol/kg fat-free mass/min/pmol/L, P < 0.05), and lower Disposition index (8.74 ± 5.72 vs 11.83 ± 7.49, P < 0.05). Compared with lean subjects without parental diabetes, β cell function was lower by ∼30% in lean subjects with parental diabetes, ∼40% in obese subjects without parental diabetes, and ∼50% in obese individuals with parental diabetes (P < 0.0001). African-Americans without parental diabetes had ∼40% lower insulin sensitivity (P < 0.001), twofold higher acute insulin secretion (P < 0.001), but ∼30% lower Disposition index (P < 0.01) compared with Caucasians without parental diabetes. Remarkably, there were no significant differences by ethnicity in these glucoregulatory measures among subjects with parental diabetes.

CONCLUSION

Offspring with parental diabetes harbor substantial impairments in glucoregulation compared with individuals without parental diabetes. Ethnic disparities in glucoregulation were abrogated by parental diabetes.

Recurrent Graves' hyperthyroidism after prolonged radioiodine-induced hypothyroidism

BACKGROUND

Radioactive iodine (RAI) is the most cost effective therapy for Graves' disease (GD). Patients with GD who have become hypothyroid after therapeutic RAI, rarely develop recurrence of disease. Herein we describe a case of recurrence of thyrotoxicosis after 2 years of hypothyroidism.

METHODS

We present the clinical features, laboratory findings, imaging and management of an unusual case of recurrent hyperthyroidism.

RESULTS

A 48-year-old male presented to the emergency room with a 2-day history of palpitation, chest discomfort and 30 pounds of weight loss. Examination was remarkable for rapid and irregular pulse, diffuse thyromegaly and brisk deep tendon reflexes but no eye changes or tremors. Laboratory tests showed thyroid-stimulating hormone (TSH) of <0.004 (0.3-5.6 mIU/ml), free thyroxine (FT4) 4.96 (0.9-1.8 ng/dl), free triiodothyronine (FT3) >20 (1.8-4.7 pg/ml), total thyroxine >800 (80-200 ng/dl). Electrocardiogram showed atrial fibrillation with rapid ventricular response. RAI uptake and scan showed a homogenous gland with 54% uptake in 6 h and 45% in 24 h. He was treated with propranolol and propylthiouracil with some clinical improvement. He subsequently underwent RAI therapy and developed hypothyroidism after 8 weeks. Hypothyroidism was treated with levothyroxine. At 2 years after RAI ablation, he again developed symptoms of hyperthyroidism and had suppressed TSH. The levothyroxine dose was stopped, 3 weeks after discontinuing levothyroxine, he remained hyperthyroid with TSH of 0.008 and FT4 of 1.62 and FT3 of 4.8. RAI uptake demonstrated 17% uptake at 24 h.

CONCLUSION

Recurrent hyperthyroidism in GD is uncommon after development of post-ablative hypothyroidism. Our case illustrates the need for continued surveillance.

Changes in skeletal muscle and organ size after a weight-loss intervention in overweight and obese type 2 diabetic patients

BACKGROUND

The effect of a weight-loss intervention on the masses of lean tissues and organs in humans is not well known.

OBJECTIVE

We studied the effects of a diet and exercise weight-loss intervention on skeletal muscle (SM) mass and selected organs over 2 y using MRI in overweight adults with type 2 diabetes.

DESIGN

Participants were 53 women and 39 men [mean ± SD: age 58 ± 7 y; body mass index (BMI; in kg/m²) 32 ± 3] enrolled in the Look AHEAD (Action for Health in Diabetes) trial and randomly assigned to an intensive lifestyle intervention (ILI) or diabetes support and education (DSE) on whom 2 y of data were collected. MRI-derived measurements of SM, heart, liver, kidney, spleen, and pancreas were acquired.

RESULTS

Adjusted for baseline weight, height, age, sex, and ethnicity, the ILI group weighed (mean ± SE) 6.6 ± 0.7 kg less after 1 y and 5.2 ± 0.7 kg less after 2 y, whereas the DSE group did not change significantly (-0.4 ± 0.6 and -1.0 ± 0.7 kg after 1 and 2 y, respectively; P-interaction < 0.001). Total SM decreased in both groups during year 1 (-1.4 ± 0.2 kg; P < 0.001) with appendicular SM regained during year 2. Liver and spleen masses decreased in the ILI group (-0.12 ± 0.02 and -0.006 ± 0.003 kg, respectively) but were unchanged in the DSE group (0.00 ± 0.02 and 0.004 ± 0.003 kg, respectively). Kidney mass decreased by 0.013 ± 0.003 kg (P < 0.001) over 2 y in both groups.

CONCLUSIONS

Decreases in liver (in Caucasians but not African Americans) and spleen were detected after a 6.2-kg weight reduction compared with a control group. SM and kidney mass decreased in both groups. Appendicular SM was regained during the second year whereas trunk SM was not. No evidence of a disproportionate loss of high-metabolic rate organs (heart, liver, kidney, spleen) compared with SM was found.

Impact of an intensive lifestyle intervention on use and cost of medical services among overweight and obese adults with type 2 diabetes: the action for health in diabetes

OBJECTIVE

To assess the relative impact of an intensive lifestyle intervention (ILI) on use and costs of health care within the Look AHEAD trial.

RESEARCH DESIGN AND METHODS

A total of 5,121 overweight or obese adults with type 2 diabetes were randomly assigned to an ILI that promoted weight loss or to a comparison condition of diabetes support and education (DSE). Use and costs of health-care services were recorded across an average of 10 years.

RESULTS

ILI led to reductions in annual hospitalizations (11%, P = 0.004), hospital days (15%, P = 0.01), and number of medications (6%, P < 0.001), resulting in cost savings for hospitalization (10%, P = 0.04) and medication (7%, P < 0.001). ILI produced a mean relative per-person 10-year cost savings of $5,280 (95% CI 3,385-7,175); however, these were not evident among individuals with a history of cardiovascular disease.

CONCLUSIONS

Compared with DSE over 10 years, ILI participants had fewer hospitalizations, fewer medications, and lower health-care costs.

Lack of racial disparity in incident prediabetes and glycemic progression among black and white offspring of parents with type 2 diabetes: the pathobiology of prediabetes in a biracial cohort (POP-ABC) study

BACKGROUND

Although the incidence of type 2 diabetes (T2D) among persons with prediabetes is well known (∼10%/y), the incidence of prediabetes among normoglycemic persons is unclear. Also, in the Diabetes Prevention Program, no racial/ethnic differences were seen in diabetes incidence, whereas marked racial/ethnic disparities are reported in the prevalence of T2D. We aimed to obtain estimates of incident prediabetes and determine whether racial disparities manifest during transition to prediabetes.

DESIGN AND METHODS

We enrolled 376 (217 black, 159 white) nondiabetic offspring of parents with T2D (mean age 44.2 y) and followed them up quarterly for 5.5 years. Assessments included anthropometry, body composition, oral glucose tolerance test, biochemistries, energy expenditure, insulin sensitivity, and insulin secretion. The primary outcome was progression to impaired fasting glucose and/or impaired glucose tolerance (or diabetes).

RESULTS

Of 343 participants with evaluable data, 101 subjects (49 white, 52 black) developed prediabetes, and 10 (4 white, 6 black) developed diabetes during a mean follow-up of 2.62 years. There was no significant racial difference in the cumulative incidence of prediabetes (32.7% white, 30% black) or combined prediabetes/diabetes (35% white, 30% black). Significant predictors of prediabetes included age, gender, trunk fat, 2-hour postload glucose (2hrPG), insulin sensitivity, and insulin secretion. In a Cox proportional-hazards model, with adjustment for age and sex, the 2hrPG and abdominal obesity were independent predictors of incident prediabetes/diabetes [relative hazards (95% confidence interval [CI]) for the 90th vs 10th percentile: trunk fat mass 2.90 (95% CI 1.74-4.82), P < .0001; 2hrPG 2.54 (95% CI 1.46-4.40), P = .0009]. Having the trunk fat mass and the 2hrPG at the 90th percentile conferred a 7-fold hazard of prediabetes compared with persons at the 10th percentile for both measures.

CONCLUSION

Black and white offspring of parents with type 2 diabetes develop prediabetes at a similar high rate of approximately 11% per year. Therefore, close surveillance, with prompt intervention to prevent dysglycemia, is warranted in persons with parental diabetes.

Pathobiology of Prediabetes in a Biracial Cohort (POP-ABC): design and methods

In contrast to the widely reported ethnic differences in prevalence, the incidence of type 2 diabetes was surprisingly similar (approximately 11%) among individuals from the different US ethnic groups in the Diabetes Prevention Program (DPP). Because DPP participants had impaired glucose tolerance (IGT) at baseline, we hypothesized that ethnic disparities are initiated at the pre-IGT stage during evolution of type 2 diabetes. The Pathobiology of Prediabetes in a Biracial Cohort (POP-ABC) is designed to test that hypothesis by tracking the natural history of early dysglycemia in a biracial cohort comprising offspring of parents with type 2 diabetes. The POP-ABC study has an enrollment target of 400 participants (200 African American, 200 Caucasian), aged 18-65 years, with at least 1 parent with type 2 diabetes. All subjects must have normal fasting glucose and/ or normal glucose tolerance, as determined by a 75-gram oral glucose tolerance test (OGTT). Subjects are recruited over approximately 3 years and followed for another 2 years, with repeated metabolic assessments. The latter include OCTT, body composition, indirect calorimetry, euglycemic clamp, beta cell function, and biochemistries. Repository specimens (DNA, RNA and proteome) are obtained for future studies. The primary outcome is the occurrence of prediabetes (ICT and/or impaired fasting glucose). The sample size provides 85% power to detect a hazard ratio of 1.75 between Black and White offspring in the primary outcome (alpha = .05). Secondary endpoints include behavioral, biochemical and socioeconomic predictors of dysglycemia. The POP-ABC study will elucidate the nosogeny of ethnic disparities in glucose dysregulation.

Admissions for diabetic ketoacidosis in ethnic minority groups in a city hospital

Hospitalization for diabetic ketoacidosis (DKA) is increasing, perhaps due to the rising incidence of DKA in patients with type 2 diabetes mellitus (T2DM). Ethnic minority groups are at increased risk for T2DM. This study aimed at elucidating the characteristics of patients with ketosis-prone diabetes in a predominantly ethnic minority population. We performed a retrospective analysis of adults admitted with DKA at the Bronx Lebanon Hospital Center, Bronx, NY over 3 years. The patients were divided into cohorts based on type of diabetes and ethnicity. The cohorts were described and compared using statistical methods. We recorded 219 cases of DKA in 168 patients, 97% of whom were African American or Hispanic. Fifty-three (32%) patients had T2DM. New-onset diabetes, which was more common in T2DM (P < .0001), and African Americans (P = .008), occurred in 42 patients (25%). Readmission with DKA was more common in the Hispanic patients with type 1 diabetes mellitus (T1DM) (P = .0001). Type 2 diabetes mellitus was more prevalent in the African Americans (P = .04). Patients with T1DM had more severe acidosis than patients with T2DM (lower pH and bicarbonate and larger anion gap; P = .03, .02, and .005, respectively). Creatinine level was higher in patients with T2DM (P = .04) who were also less likely to have identifiable precipitating causes (P = .02). Hemoglobin A(1c) level was higher in patients with new-onset diabetes (P < .05), but did not differ between those with T1DM and T2DM. Mortality, which was 2%, occurred only in the African Americans with T2DM. We conclude that DKA is an important mode of initial presentation of T2DM, with new-onset T2DM accounting for about 60% of all new cases of DKA. African American patients with T2DM, in comparison with the Hispanic patients, are more susceptible to developing DKA. Diabetic ketoacidosis could occur in T2DM without any identifiable precipitant. The rising incidence of DKA may be attributable to its increasing occurrence in T2DM; therefore, measures aimed at primary prevention of T2DM are worthwhile.