A Case of Type V Hyperlipoproteinemia Resistant to Insulin Treatment.

Type V hyperlipoproteinemia or multifactorial chylomicronemia syndrome is a rare lipid disorder triggered mainly by uncontrolled diabetes, obesity, poor diet, or particular medications. It is associated with an increased risk of acute pancreatitis and accelerated coronary artery disease which may manifest in younger age groups. We present a case of a 42-year-old male who presented to the emergency department (ED) complaining of a non-healing hand injury. Upon laboratory workup, the patient was found to have an elevated total cholesterol (TC) of 1129 mg/dL, very low levels of high-density lipoprotein (HDL) and triglycerides (TG) > 4000 mg/dL with an inability to calculate low-density lipoprotein (LDL). Lipoprotein electrophoresis revealed an actual TG level of > 7000 mg/dL, increased chylomicrons, normal B and pre-B-lipoproteins, and increased L-lipoproteins with an elevated Apolipoprotein B. Despite these derangements, the patient did not exhibit any abdominal complaints, demonstrating a normal lipase level. The physical exam was indicative of bilateral arcus senilis and obesity. Insulin drip was initiated along with intravenous (IV) hydration and it required 12 days to bring triglycerides down to less than 1000 mg/dL. The total cholesterol was also seen to be down trending to around 500 mg/dL and the HDL improved to 22 mg/dL. We present this case as a unique presentation of asymptomatic chylomicronemia resistant to insulin treatment with an elevated ApoB but with no evidence of pancreatitis or coronary artery disease.

Obesity, Inflammation, and Mortality in COVID-19: An Observational Study from the Public Health Care System of New York City.

Severe obesity increases the risk for negative outcomes in patients with coronavirus disease 2019 (COVID-19). Our objectives were to investigate the effect of BMI on in-hospital outcomes in our New York City Health and Hospitals' ethnically diverse population, further explore this effect by age, sex, race/ethnicity, and timing of admission, and, given the relationship between COVID-19 and hyperinflammation, assess the concentrations of markers of systemic inflammation in different BMI groups. A retrospective study was conducted in hospitalized patients with COVID-19 in the public health care system of New York City from 1 March 2020 to 31 October 2020. A total of 8833 patients were included in this analysis (women: 3593, median age: 62 years). The median body mass index (BMI) was 27.9 kg/m2. Both overweight and obesity were independently associated with in-hospital death. The association of overweight and obesity with death appeared to be stronger in men, younger patients, and individuals of Hispanic ethnicity. We did not observe higher concentrations of inflammatory markers in patients with obesity as compared to those without obesity. In conclusion, overweight and obesity were independently associated with in-hospital death. Obesity was not associated with higher concentrations of inflammatory markers.

Cross-sectional study evaluating the seroprevalence of SARS-CoV-2 antibodies among healthcare workers and factors associated with exposure during the first wave of the COVID-19 pandemic in New York.

OBJECTIVE: Estimate the seroprevalence of SARS-CoV-2 antibodies among New York City Health and Hospitals (NYC H+H) healthcare workers during the first wave of the COVID-19 pandemic, and describe demographic and occupational factors associated with SARS-CoV-2 antibodies among healthcare workers. DESIGN: Descriptive, observational, cross-sectional study using a convenience sample of data from SARS-CoV-2 serological tests accompanied by a demographic and occupational survey administered to healthcare workers. SETTING: A large, urban public healthcare system in NYC. PARTICIPANTS: Participants were employed by NYC H+H and either completed serological testing at NYC H+H between 30 April 2020 and 30 June 2020, or completed SARS-CoV-2 antibody testing outside of NYC H+H and were able to self-report results from the same time period. PRIMARY OUTCOME MEASURE: SARS-CoV-2 serostatus, stratified by key demographic and occupational characteristics reported through the demographic and occupational survey. RESULTS: Seven hundred and twenty-seven survey respondents were included in analysis. Participants had a mean age of 46 years (SD=12.19) and 543 (75%) were women. Two hundred and fourteen (29%) participants tested positive or reported testing positive for the presence of SARS-CoV-2 antibodies (IgG+). Characteristics associated with positive SARS-CoV-2 serostatus were Black race (25% IgG +vs 15% IgG-, p=0.001), having someone in the household with COVID-19 symptoms (49% IgG +vs 21% IgG-, p<0.001), or having a confirmed COVID-19 case in the household (25% IgG +vs 5% IgG-, p<0.001). Characteristics associated with negative SARS-CoV-2 serostatus included working on a COVID-19 patient floor (27% IgG +vs 36% IgG-, p=0.02), working in the intensive care unit (20% IgG +vs 28% IgG-, p=0.03), being employed in a clinical occupation (64% IgG +vs 78% IgG-, p<0.001) or having close contact with a patient with COVID-19 (51% IgG +vs 62% IgG-, p=0.03). CONCLUSIONS: Results underscore the significance that community factors and inequities might have on SARS-CoV-2 exposure for healthcare workers.

Retrospective Diagnosis of Malignant Struma Ovarii After Discovery of Pulmonary Metastasis.

OBJECTIVE: Malignant struma ovarii diagnosis is challenging due to its benign histologic appearance and rarity. We present a case of struma ovarii determined malignant after pulmonary metastases were incidentally discovered. METHODS: A 29-year-old female with a history of benign struma ovarii presented to the emergency room with right lower abdominal pain. Abdomen and pelvis computed tomography showed multiple bilateral pulmonary nodules, which demonstrated well-differentiated thyroid tissue on biopsy. Review of prior ovarian pathology identified features of highly differentiated thyroid carcinoma. Laboratory studies were negative for thyroglobulin (TG) antibodies, thyrotropin was 0.713 mIU/L, and TG was 169 ng/mL. The patient underwent total thyroidectomy, revealing a 0.3 cm follicular variant papillary thyroid microcarcinoma without lymphovascular invasion. An I-123 whole-body scan revealed bilateral metastases in the thigh muscles. RESULTS: I-123 whole-body scan after receiving I-131 therapy demonstrated uptake in the lungs, thyroid bed, and bilateral thighs. A computed tomography scan 5 months later revealed a decreased size of the pulmonary nodules. CONCLUSIONS: Careful histologic examination is key in making an early diagnosis of malignant struma ovarii. It requires a high index of suspicion and close histologic examination to identify malignant features, mainly the presence of cytologic overlapping ground-glass nuclei and mitotic activity or vascular invasion. Additionally, a thorough review of the imaging is needed to identify any abnormal findings suggestive of metastases. Our case demonstrates that this diagnosis may be made retrospectively after the discovery of metastases and patients can have excellent response to I-131 therapy despite a relatively low TG level.

Sex-specific impact of severe obesity in the outcomes of hospitalized patients with COVID-19: a large retrospective study from the Bronx, New York.

It has been demonstrated that obesity is an independent risk factor for worse outcomes in patients with COVID-19. Our objectives were to investigate which classes of obesity are associated with higher in-hospital mortality and to assess the association between obesity and systemic inflammation. This was a retrospective study which included consecutive hospitalized patients with COVID-19 in a tertiary center. Three thousand five hundred thirty patients were included in this analysis (female sex: 1579, median age: 65 years). The median body mass index (BMI) was 28.8 kg/m2. In the overall cohort, a J-shaped association between BMI and in-hospital mortality was depicted. In the subgroup of men, BMI 35-39.9 kg/m2 and BMI ≥40 kg/m2 were found to have significant association with higher in-hospital mortality, while only BMI ≥40 kg/m2 was found significant in the subgroup of women. No significant association between BMI and IL-6 was noted. Obesity classes II and III in men and obesity class III in women were independently associated with higher in-hospital mortality in patients with COVID-19. The male population with severe obesity was the one that mainly drove this association. No significant association between BMI and IL-6 was noted.

Insulin-sensitizing effects of vitamin D repletion mediated by adipocyte vitamin D receptor: Studies in humans and mice.

OBJECTIVE: Adipose tissue inflammation and fibrosis appear to contribute to insulin resistance in obesity. Vitamin D receptor (Vdr) genes are expressed by adipocytes, macrophages, and fibroblasts, all of which could potentially play a role in adipose tissue inflammation and fibrosis. As vitamin D has been shown to have direct anti-inflammatory effects on adipocytes, we determined whether specific vitamin D receptor-mediated effects on adipocytes could impact adipose tissue inflammation and fibrosis and ultimately insulin resistance. METHODS: We examined the effects of repleting vitamin D in 25(OH)D-deficient, insulin resistant, overweight-to-obese human subjects (n = 19). A comprehensive assessment of whole-body insulin action was undertaken with stepped euglycemic (∼90 mg/dL) hyperinsulinemic clamp studies both before and after the administration of vitamin D or placebo. Adipose tissue fibrosis and inflammation were quantified by real-time rt-PCR and immunofluorescence in subcutaneous abdominal adipose tissue. To determine whether vitamin D's effects are mediated through adipocytes, we conducted hyperinsulinemic clamp studies (4 mU/kg/min) and adipose tissue analysis using an adipocyte-specific vitamin D receptor knockout (VDR-KO) mouse model (adiponectin-Cre + VDR+/fl) following high-fat diet feeding for 12 weeks. RESULTS: 25(OH)D repletion was associated with reductions in adipose tissue expression of pro-inflammatory and pro-fibrotic genes, decreased collagen immunofluorescence, and improved hepatic insulin sensitivity in humans. Worsening trends after six months on placebo suggest progressive metabolic effects of 25(OH)D deficiency. Ad-VDR-KO mice mirrored the vitamin D-deficient humans, displaying increased adipose tissue fibrosis and inflammation and hepatic insulin resistance. CONCLUSIONS: These complementary human and rodent studies support a beneficial role of vitamin D repletion for improving hepatic insulin resistance and reducing adipose tissue inflammation and fibrosis in targeted individuals, likely via direct effects on adipocytes. These studies have far-reaching implications for understanding the role of adipocytes in mediating adipose tissue inflammation and fibrosis and ultimately impacting insulin sensitivity.

Central Regulation of Glucose Production May Be Impaired in Type 2 Diabetes.

The challenges of achieving optimal glycemic control in type 2 diabetes highlight the need for new therapies. Inappropriately elevated endogenous glucose production (EGP) is the main source of hyperglycemia in type 2 diabetes. Because activation of central ATP-sensitive potassium (KATP) channels suppresses EGP in nondiabetic rodents and humans, this study examined whether type 2 diabetic humans and rodents retain central regulation of EGP. The KATP channel activator diazoxide was administered in a randomized, placebo-controlled crossover design to eight type 2 diabetic subjects and seven age- and BMI-matched healthy control subjects. Comprehensive measures of glucose turnover and insulin sensitivity were performed during euglycemic pancreatic clamp studies following diazoxide and placebo administration. Complementary rodent clamp studies were performed in Zucker Diabetic Fatty rats. In type 2 diabetic subjects, extrapancreatic KATP channel activation with diazoxide under fixed hormonal conditions failed to suppress EGP, whereas matched control subjects demonstrated a 27% reduction in EGP (P = 0.002) with diazoxide. Diazoxide also failed to suppress EGP in diabetic rats. These results suggest that suppression of EGP by central KATP channel activation may be lost in type 2 diabetes. Restoration of central regulation of glucose metabolism could be a promising therapeutic target to reduce hyperglycemia in type 2 diabetes.

The effects of short-term vitamin D supplementation on glucose metabolism in dialysis patients: a systematic review and meta-analysis.

PURPOSE: We tested whether short-term vitamin D supplementation improves insulin resistance in patients with kidney disease, a condition with little intrinsic vitamin D activity. METHODS: PubMed, EMBASE and CENTRAL were searched for relevant observational studies and randomized clinical trials (RCTs). Random-effects models were employed for meta-analysis, and effect sizes were summarized as standardized mean difference (SMD) with 95% confidence intervals. Separate analyses were done for RCTs and non-randomized intervention studies (NRIS). RESULTS: Seventeen studies (5 RCTs and 12 NRIS) were included. The meta-analysis population (n = 131) was mostly middle aged (40-50 years), male and non-diabetic, and on hemodialysis. The duration (4-12 weeks) and type of supplementation varied between studies. Among RCTs, compared to placebo, vitamin D supplementation was associated with significant decrease in fasting glucose [SMD -1.13, (-2.11 to -0.11)] and PTH levels [SMD -1.50, (-2.95 to -0.04)] but no difference in fasting insulin levels [SMD 1.32, (-0.15 to 2.79)]. Among NRIS, there was only a significant decrease in PTH levels [SMD -1.68, (-2.55 to -0.82)] between pre- and post-vitamin D treatment levels. CONCLUSIONS: Short-term (4-12 weeks) supplementation with vitamin D is associated with lower fasting glucose levels in ESRD with no change in fasting insulin levels. However, the findings from this study are limited by the studies that were used in the meta-analysis, which were mostly small, used multiple different vitamin D compounds and dosing regimens, and had large heterogeneity, and funnel plots showed that there was a dearth of studies with null or negative finding. Therefore, larger RCTs need to be performed to answer this important clinical question.

Insulin sensitizing and anti-inflammatory effects of thiazolidinediones are heightened in obese patients.

OBJECTIVE: The American Diabetes Association has called for further research on how patients' demographics should determine drug choices for individuals with type 2 diabetes mellitus (T2DM). Here, using in-depth physiology studies, we investigate whether obese patients with T2DM are likely to benefit from thiazolidinediones, medications with a known adverse effect of weight gain. MATERIALS AND METHODS: Eleven obese and 7 nonobese individuals with T2DM participated in this randomized, placebo-controlled, double-blind, crossover study. Each subject underwent a pair of "stepped" pancreatic clamp studies with subcutaneous adipose tissue biopsies after 21 days of pioglitazone (45 mg) or placebo. RESULTS: Obese subjects demonstrated significant decreases in insulin resistance and many adipose inflammatory parameters with pioglitazone relative to placebo. Specifically, significant improvements in glucose infusion rates, suppression of hepatic glucose production, and whole fat expression of certain inflammatory markers (IL-6, IL-1B, and inducible nitric oxide synthase) were observed in the obese subjects but not in the nonobese subjects. Additionally, adipose tissue from the obese subjects demonstrated reduced infiltration of macrophages, dendritic cells, and neutrophils as well as increased expression of factors associated with fat "browning" (peroxisome proliferator-activated receptor gamma coactivator-1α and uncoupling protein-1). CONCLUSIONS: These findings support the efficacy of pioglitazone to improve insulin resistance and reduce adipose tissue inflammation in obese patients with T2DM.

Reduced adipose tissue macrophage content is associated with improved insulin sensitivity in thiazolidinedione-treated diabetic humans.

Obesity is associated with increased adipose tissue macrophage (ATM) infiltration, and rodent studies suggest that inflammatory factors produced by ATMs contribute to insulin resistance and type 2 diabetes. However, a relationship between ATM content and insulin resistance has not been clearly established in humans. Since thiazolidinediones attenuate adipose tissue inflammation and improve insulin sensitivity, we examined the temporal relationship of the effects of pioglitazone on these two parameters. The effect of 10 and 21 days of pioglitazone treatment on insulin sensitivity in 26 diabetic subjects was assessed by hyperinsulinemic-euglycemic clamp studies. Because chemoattractant factors, cytokines, and immune cells have been implicated in regulating the recruitment of ATMs, we studied their temporal relationship to changes in ATM content. Improved hepatic and peripheral insulin sensitivity was seen after 21 days of pioglitazone. We found early reductions in macrophage chemoattractant factors after only 10 days of pioglitazone, followed by a 69% reduction in ATM content at 21 days and reduced ATM activation at both time points. Although markers for dendritic cells and neutrophils were reduced at both time points, there were no significant changes in regulatory T cells. These results are consistent with an association between adipose macrophage content and systemic insulin resistance in humans.

Fatty acid-induced production of plasminogen activator inhibitor-1 by adipose macrophages is greater in middle-aged versus younger adult participants.

BACKGROUND: Human aging is associated with heightened risk of diabetes and cardiovascular disease. Increased fat mass may contribute to age-related diseases by harboring inflammatory macrophages that produce metabolically important proteins such as plasminogen activator inhibitor-1 (PAI-1). Elevated PAI-1 concentrations have been implicated in the pathogenesis of such aging-related conditions as insulin resistance, obesity, and atherosclerosis. We have previously reported that increased plasma free fatty acid (FFA) concentrations augment both circulating PAI-1 concentrations and PAI-1 production by adipose tissue macrophages (ATMs). METHODS: Because increasing age is associated with increased infiltration and reactivity of adipose macrophages, we performed euglycemic-hyperinsulinemic clamp studies and adipose tissue biopsies with and without elevated FFA concentrations in 31 nondiabetic participants stratified by age, to determine whether middle-aged individuals manifest heightened insulin resistance and PAI-1 production by ATMs in response to elevated nutrient signals relative to their young adult peers. RESULTS: We observed that elevating FFA concentrations under euglycemic-hyperinsulinemic clamp conditions induced the same degree of insulin resistance in both middle-aged and younger body mass index-matched adults, whereas systemic PAI-1 concentrations were significantly increased in the middle-aged group. Likewise, elevated FFA and insulin concentrations induced larger increases in PAI-1 gene expression in the whole fat and ATMs of middle-aged compared with younger adult participants. CONCLUSIONS: These studies reveal a heightened adipose inflammatory response to increased FFA and insulin availability in middle-aged individuals relative to younger adults, suggesting that increased susceptibility to the effects of fatty acid excess may contribute to the pathogenesis of age-related diseases.

Glycemic control and cardiovascular disease: what's a doctor to do?

Cardiovascular disease (CVD) remains the leading cause of morbidity and mortality in individuals with diabetes mellitus. Moreover, rates of CVD mortality are two to four times higher in diabetes than in those without diabetes. It was conventional thinking that achieving near-normoglycemia would help reduce CVD risk and overall mortality in type 2 diabetes mellitus. Several recent large trials attempted to answer this question using a randomized control trial design with a conventional therapy and an intensive control arm. Surprisingly, these trials did not demonstrate neither mortality nor a CVD advantage with intensive glycemic control. Moreover, some studies (e.g., the ACCORD [Action to Control Cardiovascular Risk in Diabetes] study) showed increased mortality in the intensive control arm. In this review, our goal is to summarize the findings of the major trials in this field and to explore the potential reasons for why these trials had largely negative results. We conclude with some lessons that may be applied to the clinical management of patients with diabetes.

Pilot study of resveratrol in older adults with impaired glucose tolerance.

BACKGROUND: Resveratrol, a plant-derived polyphenol, has shown promising effects on insulin sensitivity and glucose tolerance in animal models and is also reported to have cardioprotective properties, but human studies are limited. In a pilot study, we tested the hypothesis that resveratrol improves glucose metabolism and vascular function in older adults with impaired glucose tolerance (IGT). METHODS: Ten subjects aged 72 ± 3 years (M ± SD) with IGT were enrolled in a 4-week open-label study of resveratrol (daily dose 1, 1.5, or 2 g). Following a standard mixed meal (110 g carbohydrate, 20 g protein, 20 g fat), we measured 3-hour glucose and insulin area under the curve (AUC), insulin sensitivity (Matsuda index), and secretion (corrected insulin response at 30 minutes). Endothelial function was assessed by reactive hyperemia peripheral arterial tonometry (reactive hyperemia index) before and 90 minutes postmeal. Results did not differ by dose, so data were combined for analysis. RESULTS: At baseline, body mass index was 29 ± 5 kg/m(2), fasting plasma glucose 110 ± 13 mg/dL, and 2-hour glucose 183 ± 33 mg/dL. After 4 weeks of resveratrol, fasting plasma glucose was unchanged, but peak postmeal (185 ± 10 vs 166 ± 9 mg/dL, p = .003) and 3-hour glucose AUC (469 ± 23 vs 428 ± 19, p = .001) declined. Matsuda index improved (3.1 ± 0.5 vs 3.8 ± 0.5, p = .03), and corrected insulin response at 30 minutes was unchanged (0.6 ± 0.1 vs 0.5 ± 0.5, p = .49). There was a trend toward improved postmeal reactive hyperemia index (baseline vs resveratrol postmeal delta -0.4 ± 0.2 vs 0.2 ± 0.3, p = .06). Weight, blood pressure, and lipids were unchanged. CONCLUSIONS: At doses between 1 and 2 g/day, resveratrol improves insulin sensitivity and postmeal plasma glucose in subjects with IGT. These preliminary findings support the conduct of larger studies to further investigate the effects of resveratrol on metabolism and vascular function.

Activation of K(ATP) channels suppresses glucose production in humans.

Increased endogenous glucose production (EGP) is a hallmark of type 2 diabetes mellitus. While there is evidence for central regulation of EGP by activation of hypothalamic ATP-sensitive potassium (K(ATP)) channels in rodents, whether these central pathways contribute to regulation of EGP in humans remains to be determined. Here we present evidence for central nervous system regulation of EGP in humans that is consistent with complementary rodent studies. Oral administration of the K(ATP) channel activator diazoxide under fixed hormonal conditions substantially decreased EGP in nondiabetic humans and Sprague Dawley rats. In rats, comparable doses of oral diazoxide attained appreciable concentrations in the cerebrospinal fluid, and the effects of oral diazoxide were abolished by i.c.v. administration of the K(ATP) channel blocker glibenclamide. These results suggest that activation of hypothalamic K(ATP) channels may be an important regulator of EGP in humans and that this pathway could be a target for treatment of hyperglycemia in type 2 diabetes mellitus.

Adipocyte-derived factors potentiate nutrient-induced production of plasminogen activator inhibitor-1 by macrophages.

Macrophages are more abundant in adipose tissue from obese individuals than from those of normal weight and may contribute to the metabolic consequences of obesity by producing various circulating factors. One of these factors is plasminogen activator inhibitor-1 (PAI-1), which contributes to both atherosclerosis and insulin resistance. Because nutritional factors appear to regulate PAI-1 expression, we hypothesized that exposure to fatty acids and adipocyte secretory products could stimulate production of PAI-1 by adipose macrophages. Increased free fatty acid (FFA) concentrations in blood for 5 hours in nondiabetic, overweight subjects markedly suppressed insulin-stimulated glucose uptake and raised circulating PAI-1 concentrations, with a concomitant increase in the expression of the PAI-1 gene in adipose tissue. FFAs also rapidly increased PAI-1 gene expression in adipose macrophages and PAI-1 protein immunofluorescence surrounding these cells. By contrast, PAI-1 expression in circulating monocytes was very low and was not affected by raising the concentration of FFAs. Medium from cultured adipocytes stimulated PAI-1 expression in cultured macrophages and potentiated the increase in PAI-1 messenger RNA expression in response to FFAs. Together, our data suggest that adipocyte-derived factors prime adipose macrophages so that they respond to nutritional signals (FFAs) by releasing a key inflammatory adipokine, PAI-1.

Inhibiting gluconeogenesis prevents fatty acid-induced increases in endogenous glucose production.

Glucose effectiveness, the ability of glucose per se to suppress endogenous glucose production (EGP), is lost in type 2 diabetes mellitus (T2DM). Free fatty acids (FFA) may contribute to this loss of glucose effectiveness in T2DM by increasing gluconeogenesis (GNG) and impairing the response to hyperglycemia. Thus, we first examined the effects of increasing plasma FFA levels for 3, 6, or 16 h on glucose effectiveness in nondiabetic subjects. Under fixed hormonal conditions, hyperglycemia suppressed EGP by 61% in nondiabetic subjects. Raising FFA levels with Liposyn infusion for > or =3 h reduced the normal suppressive effect of glucose by one-half. Second, we hypothesized that inhibiting GNG would prevent the negative impact of FFA on glucose effectiveness. Raising plasma FFA levels increased gluconeogenesis by approximately 52% during euglycemia and blunted the suppression of EGP by hyperglycemia. Infusion of ethanol rapidly inhibited GNG and doubled the suppression of EGP by hyperglycemia, thereby restoring glucose effectiveness. In conclusion, elevated FFA levels rapidly increased GNG and impaired hepatic glucose effectiveness in nondiabetic subjects. Inhibiting GNG could have therapeutic potential in restoring the regulation of glucose production in type 2 diabetes mellitus.

Increased intrahepatic triglyceride is associated with peripheral insulin resistance: in vivo MR imaging and spectroscopy studies.

Recent studies have indicated that the mass/content of intramyocellular lipid (IMCL), intrahepatic triglyceride (IHTG), visceral fat (VF), and even deep abdominal subcutaneous fat (SF) may all be correlated with insulin resistance. Since simultaneous measurements of these parameters have not been reported, the relative strength of their associations with insulin action is not known. Therefore, the goals of this study were 1) to simultaneously measure IMCL, IHTG, VF, and abdominal SF in the same nondiabetic individuals using noninvasive (1)H-magnetic resonance spectroscopy (MRS) and magnetic resonance imaging (MRI) and 2) to examine how these fat stores are correlated with systemic insulin sensitivity as measured by whole body glucose disposal (R(d)) during euglycemic-hyperinsulinemic clamp studies. Positive correlations were observed among IMCL, IHTG, and VF. There were significant inverse correlations between whole body R(d) and both IMCL and VF. Notably, there was a particularly tight inverse correlation between IHTG and whole body R(d) (r = -0.86, P < 0.001), consistent with an association between liver fat and peripheral insulin sensitivity. This novel finding suggests that hepatic triglyceride accumulation has important systemic consequences that may adversely affect insulin sensitivity in other tissues.