Metabolic and histological implications of intrahepatic triglyceride content in nonalcoholic fatty liver disease.

The cut-off point of intrahepatic triglyceride (IHTG) content to define nonalcoholic fatty liver disease (NAFLD) by proton magnetic resonance spectroscopy (1 H-MRS) was established based on the 95th percentile in a group of healthy individuals (i.e., ≥5.56%). Whether this threshold correlates with metabolic and histological changes and whether a further accumulation of IHTG is associated with worsening of these parameters has not been properly assessed in a large cohort of patients. In this cross-sectional study, 352 subjects were carefully characterized with the following studies: liver 1 H-MRS; euglycemic insulin clamp with measurement of glucose turnover; oral glucose tolerance test; and a liver biopsy. Hepatic insulin sensitivity (suppression of endogenous glucose production by insulin) was affected early on after IHTG content was ∼1.5% and remained uniformly impaired (∼40%-45%), regardless of further IHTG accumulation. Skeletal muscle insulin sensitivity showed a gradual impairment at low degrees of IHTG accumulation, but remained unchanged after IHTG content reached the ∼6 ± 2% threshold. A similar pattern was observed for metabolic changes typically associated with NAFLD, such as hypertriglyceridemia and low high-density lipoprotein cholesterol (HDL-C). In contrast, adipose tissue insulin sensitivity (suppression of free fatty acids by insulin) showed a continuous worsening across the spectrum of IHTG accumulation in NAFLD (r = -0.38; P < 0.001). Histological severity of liver disease (inflammation, ballooning, and fibrosis) was not associated with the amount of IHTG content. CONCLUSION: IHTG accumulation is strongly associated with adipose tissue insulin resistance (IR), supporting the current theory of lipotoxicity as a driver of IHTG accumulation. Once IHTG accumulation reaches ∼6 ± 2%, skeletal muscle IR, hypertriglyceridemia, and low HDL-C become fully established. Histological activity appears to have an early threshold and is not significantly influenced by increasing amounts of IHTG accumulation. (Hepatology 2017;65:1132-1144).

Metabolic Impact of Nonalcoholic Steatohepatitis in Obese Patients With Type 2 Diabetes.

OBJECTIVE: Nonalcoholic steatohepatitis (NASH) is increasingly common in obese patients. However, its metabolic consequences in patients with type 2 diabetes mellitus (T2DM) are unknown. RESEARCH DESIGN AND METHODS: We studied 154 obese patients divided in four groups: 1) control (no T2DM or NAFLD), 2) T2DM without NAFLD, 3) T2DM with isolated steatosis, and 4) T2DM with NASH. We evaluated intrahepatic triglycerides by proton MRS ((1)H-MRS) and assessed insulin secretion/resistance during an oral glucose tolerance test and a euglycemic-hyperinsulinemic clamp with glucose turnover measurements. RESULTS: No significant differences among groups were observed in sex, BMI, or total body fat. Metabolic parameters worsened progressively with the presence of T2DM and the development of hepatic steatosis, with worse hyperinsulinemia, insulin resistance, and dyslipidemia (hypertriglyceridemia and low HDL cholesterol) in those with NASH (P < 0.001). Compared with isolated steatosis, NASH was associated with more dysfunctional and insulin-resistant adipose tissue (either as insulin suppression of plasma FFA [33 ± 3 vs. 48 ± 6%] or adipose tissue insulin resistance index [9.8 ± 1.0 vs. 5.9 ± 0.8 mmol/L ⋅ µIU/mL]; both P < 0.03). Furthermore, insulin suppression of plasma FFA correlated well with hepatic steatosis (r = -0.62; P < 0.001) and severity of steatohepatitis (rs = -0.52; P < 0.001). Hepatic insulin sensitivity was also more significantly impaired among patients with T2DM and NASH, both fasting and with increasing insulin levels within the physiological range (10 to 140 µIU/mL), compared with other groups. CONCLUSIONS: In obese patients with T2DM, the presence of NAFLD is associated with more severe hyperinsulinemia, dyslipidemia, and adipose tissue/hepatic insulin resistance compared with patients without NAFLD. The unfavorable metabolic profile linked to NAFLD should prompt strategies to identify and treat this population early on.

Hepatic Steatosis and Insulin Resistance, But Not Steatohepatitis, Promote Atherogenic Dyslipidemia in NAFLD.

CONTEXT: Patients with nonalcoholic fatty liver disease (NAFLD) are at increased risk of cardiovascular disease, and atherogenic lipoproteins may play an important role. OBJECTIVE: The objective of the study was to determine the contribution of the severity of steatohepatitis to atherogenic dyslipidemia in patients with NAFLD. DESIGN: This was a cross-sectional study. SETTING: The study was conducted at a university hospital. PATIENTS: Patients were recruited from outpatient clinics or from the general population (n = 188). INTERVENTIONS: Measurement of hepatic triglyceride content by magnetic resonance spectroscopy, histology (liver biopsy), metabolic profile by means of an oral glucose tolerance test, and lipoprotein analyses were performed. OUTCOMES: Outcomes measured included standard lipids, lipoprotein subfraction analysis (apolipoprotein B/A1 levels, low-density lipoprotein (LDL) particle size/phenotype, and LDL/high-density lipoprotein subfractions), and insulin resistance. RESULTS: Patients with NAFLD had severe insulin resistance, especially at the level of the adipose tissue, when compared with patients without NAFLD. Despite small differences in triglycerides and high-density lipoprotein-cholesterol, patients with NAFLD had a significantly higher plasma apolipoprotein B to apolipoprotein A1 ratio (0.66 ± 0.02 vs 0.58 ± 0.02, P = .01) and smaller LDL particle size (216.2 ± 0.7 vs 219.4 ± 1.1 Å, P = .01). Of note, these differences between patients with/without NAFLD were independent of the presence of obesity. Severity of steatohepatitis did not significantly influence the lipoprotein profile. Worse atherogenic dyslipidemia was best predicted by the degree of liver fat accumulation and adipose tissue and systemic insulin resistance. CONCLUSIONS: NAFLD was associated with a worse atherogenic lipoprotein profile, regardless of similar body mass index and other clinical parameters. We speculate that this lipoprotein profile is driven mostly by liver fat content and insulin resistance and appears not to be worsened by obesity or the severity of liver disease (nonalcoholic steatohepatitis).

The cytologic diagnosis of epithelioid myxofibrosarcoma: a case report.

The epithelioid variant of myxofibrosarcoma is a rare but recently described entity. We report a case of an elderly woman who presented with a slowly enlarging mass of the right lower extremity. Fine-needle aspiration (FNA) cytology revealed a malignant epithelioid neoplasm. The smears of the aspirate material were highly cellular and contained a dominant population of cells with uniform round-to-oval nuclei and cytoplasmic vacuolization, arranged in loosely cohesive aggregates and linear arrays within a myxoid background. A second minor population of cells consisted of aggregates of bland spindled cells. On resection, the neoplasm proved to be an epithelioid myxofibrosarcoma. To our knowledge, the cytologic features of epithelioid myxofibrosarcoma have not previously been documented. Herein, we discuss the cytologic features of epithelioid myxofibrosarcoma as seen on FNA biopsy and its distinction from other epithelioid neoplasms of soft tissue.