Change in hepatic fat content measured by MRI does not predict treatment-induced histological improvement of steatohepatitis.

BACKGROUND & AIMS: Proof-of-concept studies frequently assess changes in intrahepatic triglyceride (IHTG) content by magnetic resonance-based techniques as a surrogate marker of histology. The aim of this study was to establish how reliable this strategy is to predict changes in liver histology in patients with non-alcoholic steatohepatitis (NASH). METHODS: Patients with NASH who had participated in our prior randomized controlled trials of pioglitazone with complete paired data for IHTG content by magnetic resonance spectroscopy and liver histology were included in the study. RESULTS: A total of 121 patients were included. Changes in IHTG were assessed in several ways: as a continuous variable (correlations), as categorical groups (IHTG change ≥0%; or IHTG reduction of 1-30%; 31-50%; 51-70%; or >70%), and in a binomial way as steatosis resolution or not (defined as achieving IHTG <5.56%). Changes in IHTG correlated with steatosis on histology (r = 0.54; p <0.01). However, the magnitude of IHTG reduction was not associated with the rate of response of the primary histological outcome (2-point improvement in the NAFLD activity score from 2 different parameters, without worsening of fibrosis) or resolution of NASH without worsening of fibrosis, neither in patients receiving pioglitazone nor placebo. Changes in lobular inflammation, hepatocyte ballooning, or liver fibrosis were also independent of changes in IHTG, irrespective of treatment arm. Steatosis resolution was not associated with better histological outcomes either. CONCLUSIONS: Changes in IHTG predict changes in steatosis but not of other liver histological parameters. This implies that IHTG response to treatment should be interpreted with caution, as it may not be as reliable as previously believed to predict a treatment's overall clinical efficacy in patients with NASH. LAY SUMMARY: Quantification of liver fat by magnetic resonance imaging (MRI) is currently used to assess treatment responses in patients with fatty liver, with the assumption that improvements in liver fat translate into less inflammation, necrosis, and fibrosis in the liver. However, in this article, we showed that changes in liver fat do not necessarily translate into changes in these parameters. This means that MRI may not be as useful to assess treatment response in patients with fatty liver as previously believed.

Response to Pioglitazone in Patients With Nonalcoholic Steatohepatitis With vs Without Type 2 Diabetes.

BACKGROUND & AIMS: Pioglitazone is effective for long-term treatment of patients with nonalcoholic steatohepatitis (NASH) with prediabetes or type 2 diabetes. However, it is not clear how the presence of type 2 diabetes affects the drug's efficacy. We compared metabolic and histologic responses to pioglitazone in patients with NASH and prediabetes vs type 2 diabetes. METHODS: We performed a prospective study of adults with biopsy-proven NASH (52 with type 2 diabetes and 49 with prediabetes), enrolled from the general population of San Antonio, Texas, from 2008 through 2014. After a run-in period of approximately 4 weeks, when all baseline measurements were made (liver magnetic resonance proton spectroscopy, euglycemic insulin clamp with glucose turnover measurements, dual-energy absorptiometry, and liver biopsy), subjects were randomly assigned to groups given pioglitazone or placebo (45 mg/d) for 18 months; all procedures performed at baseline were then repeated. The primary outcome was a reduction in nonalcoholic fatty liver disease activity score of 2 points or more (for at least 2 components) without worsening of fibrosis (and expressed as difference vs placebo). Secondary outcomes included NASH resolution, individual histologic components, intrahepatic triglyceride content (measured by 1H magnetic resonance spectroscopy), and insulin sensitivity (measured by euglycemic insulin clamp). RESULTS: The primary outcome was met by 48% of patients with type 2 diabetes vs 46% without diabetes. Resolution of NASH was achieved in 44% of patients with type 2 diabetes vs 26% without diabetes. A significant reduction in fibrosis, from baseline, was observed only in patients with type 2 diabetes (P = .035). Intrahepatic triglyceride content was reduced by 11% ± 2% in patients with diabetes vs a reduction of 9% ± 2% in patients without diabetes (P = .62); the plasma level of alanine aminotransferase was reduced by 50 ± 10 U/L in patients with diabetes vs a reduction of 36 ± 5 U/L in patients without diabetes (P = .22). Pioglitazone was associated with a significantly greater insulin sensitivity in adipose tissue of patients with diabetes vs without diabetes (P < .001), but nonsignificant differences in responses in hepatic (P = .49) and skeletal muscle (P = .32) insulin sensitivity. CONCLUSIONS: In a prospective study, we found pioglitazone to be effective in patients with and without type 2 diabetes. However, pioglitazone reduced liver fibrosis and increased adipose tissue insulin sensitivity at significantly greater levels in patients with type 2 diabetes than in patients with prediabetes. Further studies are needed to determine the mechanisms by which pioglitazone reduces liver disease in patients with type 2 diabetes. ClinicalTrials.gov: NCT00994682.

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).

Long-Term Pioglitazone Treatment for Patients With Nonalcoholic Steatohepatitis and Prediabetes or Type 2 Diabetes Mellitus: A Randomized Trial.

BACKGROUND: The metabolic defects of nonalcoholic steatohepatitis (NASH) and prediabetes or type 2 diabetes mellitus (T2DM) seem to be specifically targeted by pioglitazone. However, information about its long-term use in this population is limited. OBJECTIVE: To determine the efficacy and safety of long-term pioglitazone treatment in patients with NASH and prediabetes or T2DM. DESIGN: Randomized, double-blind, placebo-controlled trial. (ClinicalTrials.gov: NCT00994682). SETTING: University hospital. PARTICIPANTS: Patients (n = 101) with prediabetes or T2DM and biopsy-proven NASH were recruited from the general population and outpatient clinics. INTERVENTION: All patients were prescribed a hypocaloric diet (500-kcal/d deficit from weight-maintaining caloric intake) and then randomly assigned to pioglitazone, 45 mg/d, or placebo for 18 months, followed by an 18-month open-label phase with pioglitazone treatment. MEASUREMENTS: The primary outcome was a reduction of at least 2 points in the nonalcoholic fatty liver disease activity score in 2 histologic categories without worsening of fibrosis. Secondary outcomes included other histologic outcomes, hepatic triglyceride content measured by magnetic resonance and proton spectroscopy, and metabolic parameters. RESULTS: Among patients randomly assigned to pioglitazone, 58% achieved the primary outcome (treatment difference, 41 percentage points [95% CI, 23 to 59 percentage points]) and 51% had resolution of NASH (treatment difference, 32 percentage points [CI, 13 to 51 percentage points]) (P < 0.001 for each). Pioglitazone treatment also was associated with improvement in individual histologic scores, including the fibrosis score (treatment difference, -0.5 [CI, -0.9 to 0.0]; P = 0.039); reduced hepatic triglyceride content from 19% to 7% (treatment difference, -7 percentage points [CI, -10 to -4 percentage points]; P < 0.001); and improved adipose tissue, hepatic, and muscle insulin sensitivity (P < 0.001 vs. placebo for all). All 18-month metabolic and histologic improvements persisted over 36 months of therapy. The overall rate of adverse events did not differ between groups, although weight gain was greater with pioglitazone (2.5 kg vs. placebo). LIMITATION: Single-center study. CONCLUSION: Long-term pioglitazone treatment is safe and effective in patients with prediabetes or T2DM and NASH. PRIMARY FUNDING SOURCE: Burroughs Wellcome Fund and American Diabetes Association.

The role of liver fat and insulin resistance as determinants of plasma aminotransferase elevation in nonalcoholic fatty liver disease.

UNLABELLED: Plasma aminotransferases (aspartate aminotransferase [AST] and alanine aminotransferase [ALT]) are usually increased in patients with nonalcoholic fatty liver disease (NAFLD). However, the factors behind their elevation remain unclear. The aim of this study was to assess the role of insulin resistance (IR) and liver triglyceride content in relation to histology in patients with NAFLD/nonalcoholic steatohepatitis (NASH) with normal or elevated ALT levels. To this end, we enrolled 440 patients, divided into three groups: no NAFLD (n = 60); NAFLD with normal ALT (n = 165); and NAFLD with elevated ALT (n = 215). We measured: (1) liver fat by proton magnetic resonance spectroscopy ((1)H-MRS); (2) severity of liver disease by biopsy (n = 293); and (3) insulin sensitivity in liver, muscle, and adipose tissue by a euglycemic hyperinsulinemic clamp with 3-(3)H-glucose. Patients with NAFLD and elevated ALT, even when well matched for body mass index to those with normal ALT, had worse adipose tissue insulin resistance (ATIR; P < 0.0001), higher liver triglyceride content (P < 0.0001), and lower plasma adiponectin (P < 0.05), but no differences in hepatic insulin resistance. Similar results were found when only patients with NASH were compared: both ATIR (P < 0.0001) and liver triglyceride content by (1)H-MRS (P < 0.0001) were worse in NASH with elevated ALT. Consistent with the (1)H-MRS data, steatosis on liver biopsy was also significantly increased in patients with NASH and elevated ALT levels (P < 0.0001). However, and most important, there were no differences in inflammation (P = 0.62), ballooning (P = 0.13), or fibrosis (P = 0.12). CONCLUSION: In patients with NAFLD or NASH, ATIR (but not HIR) and liver triglyceride content are major factors in the elevation of plasma aminotransferase levels. Patients with normal versus elevated ALT had similar severity of NASH, suggesting that plasma aminotransferase levels are misleading parameters for guiding clinical management.

Relationship of vitamin D with insulin resistance and disease severity in non-alcoholic steatohepatitis.

BACKGROUND & AIMS: The role of plasma vitamin D deficiency in the development of non-alcoholic fatty liver disease (NAFLD) and steatohepatitis (NASH) remains poorly understood. Previous studies have suggested a role for vitamin D deficiency in the pathogenesis of NAFLD/NASH, but they have been rather small, and/or NAFLD was diagnosed using only aminotransferases or liver ultrasound. This study aimed to assess the role of vitamin D deficiency in relationship to liver fat accumulation and severity of NASH. METHODS: A total of 239 patients were recruited and state-of-the-art techniques were used to measure insulin resistance (euglycemic insulin clamp with 3-(3)H-glucose), liver fat accumulation (magnetic resonance spectroscopy or (1)H-MRS), total body fat (dual energy X-ray absorptiometry), and severity of liver disease (liver biopsy). RESULTS: Patients were divided into 3 groups according to plasma 25-hydroxyvitamin D levels (normal: >30 ng/ml; insufficiency: 20-30 ng/ml; deficiency: <20 ng/ml). When well-matched for clinical parameters (BMI, total adiposity, or prevalence of prediabetes/type 2 diabetes), no significant differences were observed among groups in terms of skeletal muscle, hepatic, or adipose tissue insulin sensitivity, the amount of liver fat by (1)H-MRS, or the severity of histological inflammation, ballooning, or fibrosis. Patients were then divided according to liver histology into those with definite NASH and those without NASH. Although patients with NASH had higher insulin resistance, plasma vitamin D concentrations were similar between both groups. CONCLUSIONS: Our results suggest that plasma vitamin D levels are not associated with insulin resistance, the amount of liver fat accumulation, or the severity of NASH.

Relationship between disease severity, hyperinsulinemia, and impaired insulin clearance in patients with nonalcoholic steatohepatitis.

UNLABELLED: Hyperinsulinemia is believed to play a key role in the pathogenesis of nonalcoholic steatohepatitis (NASH) and associated cardiovascular risk. However, the relative contribution of insulin clearance to hyperinsulinemia and its relationship to liver histology have not been carefully evaluated before. To examine this, we enrolled 190 patients (32 without nonalcoholic fatty liver disease [NAFLD], 36 with simple steatosis [SS], and 122 with biopsy-proven NASH). Insulin secretion and hepatic insulin clearance were estimated by means of an oral glucose tolerance test, whereas peripheral insulin sensitivity and whole-body insulin clearance were measured during a euglycemic insulin clamp. A liver biopsy was performed to assess histology (grade/stage). Patients with NASH had similar hepatic insulin sensitivity, compared to patients with SS, but more severe adipose tissue insulin resistance and worse hyperinsulinemia. Patients with SS and NASH had a similar ∼30% reduction (P<0.01) in hepatic insulin clearance, when compared to patients without NAFLD. Reduced hepatic insulin clearance was not associated with severity of inflammation, ballooning, and fibrosis. In contrast, worse histological inflammation and ballooning (but not steatosis or fibrosis) were associated with a progressive reduction in whole-body insulin clearance (P<0.001 for trend). There was no significant difference in insulin secretion between patients with SS versus NASH. CONCLUSION: Decreased hepatic insulin clearance develops with a mild increase in liver fat (LFAT) accumulation. It appears to be largely driven by hepatic steatosis, whereas steatohepatitis is more closely associated with reduced whole-body insulin clearance. Hyperinsulinemia in NAFLD correlated strongly with impaired insulin clearance, but not with insulin secretion. Strategies that reduce LFAT and improve insulin clearance hold the potential to revert the unfavorable effects of hyperinsulinemia in these patients.

Clinical value of liver ultrasound for the diagnosis of nonalcoholic fatty liver disease in overweight and obese patients.

BACKGROUND & AIMS: Liver ultrasound (US) is usually used in the clinical setting for the diagnosis and follow-up of patients with nonalcoholic fatty liver disease (NAFLD). However, no large study has carefully assessed its performance using a semiquantitative ultrasonographic scoring system in overweight/obese patients, in comparison to magnetic resonance spectroscopy ((1) H-MRS) and histology. METHODS: We recruited 146 patients and performed: a liver US using a 5-parameter scoring system, a liver (1) H-MRS to quantify liver fat content, and a liver biopsy to assess histology. All measurements were repeated in a subgroup of patients (n = 62) after 18 months of follow-up. RESULTS: The performance of liver US (parenchymal echo alone) was rather modest, and significantly worse than (1) H-MRS (AUROC: 0.82 [0.69-0.94] vs. 0.96 [0.90-1.00]; P = 0.04). However, the AUROC improved when different echographic parameters were taken into account (AUROC: 0.89 [0.83-0.96], P = 0.15 against (1) H-MRS). Optimum sensitivity for liver US was achieved at a liver fat content ≥12.5%, suggesting that below this threshold, liver US is less sensitive. Liver (1) H-MRS showed a high accuracy for the diagnosis of NAFLD, and correlated strongly with histological steatosis (r = 0.73, P < 0.0001). None of the imaging tests was adequate enough to predict changes over time in histology. CONCLUSIONS: Despite its widespread use, liver US has several important limitations that healthcare providers should recognize, particularly because of its low sensitivity. Using a combination of echographic parameters, liver US showed a significant improvement in its diagnostic performance, but still was of limited value for monitoring treatment over time.

Limited value of plasma cytokeratin-18 as a biomarker for NASH and fibrosis in patients with non-alcoholic fatty liver disease.

BACKGROUND & AIMS: Liver biopsy is the only reliable way of diagnosing and staging NASH but its invasive nature limits its use. Plasma caspase-generated cytokeratin-18 fragments (CK-18) have been proposed as a non-invasive alternative. We studied its clinical value in a large multiethnic NAFLD population and examined its relationship to clinical/metabolic/histological parameters. METHODS: 424 middle-aged subjects in whom we measured adipose tissue, liver and muscle insulin resistance (IR), liver fat by MRS (n=275) and histology (n=318). RESULTS: Median CK-18 were elevated in patients with vs. without NAFLD by MRS (209 [IQR: 137-329] vs. 122 [IQR: 98-155]U/L) or with vs. without NASH (232 [IQR: 151-387] vs. 170 [IQR: 135-234]U/L, both p<0.001). Plasma CK-18 raised significantly with any increase in steatosis, inflammation and fibrosis, but there was a significant overlap across disease severity. The CK-18 AUROC to predict NAFLD, NASH or fibrosis were 0.77 (95% CI=0.71-0.84), 0.65 (95% CI=0.59-0.71) and 0.68 (95% CI=0.61-0.75), respectively. The overall sensitivity/specificity for NAFLD, NASH and fibrosis were 63% (57-70%)/83% (69-92%), 58% (51-65%)/68% (59-76%) and 54% (44-63%)/85% (75-92%), respectively. CK-18 correlated most strongly with ALT (r=0.57, p<0.0001) and adipose tissue IR (insulin-suppression of FFA: r=-0.43; p<0.001), less with steatosis, lobular inflammation and fibrosis (r=0.28-0.34, all p<0.001), but not with ballooning, BMI, metabolic syndrome or T2DM. CONCLUSIONS: Plasma CK-18 has a high specificity for NAFLD and fibrosis, but its limited sensitivity makes it inadequate as a screening test for staging NASH. Whether combined as a diagnostic panel with other biomarkers or clinical/laboratory tests may prove useful requires further study.

Effect of adipose tissue insulin resistance on metabolic parameters and liver histology in obese patients with nonalcoholic fatty liver disease.

UNLABELLED: The role of adipose tissue insulin resistance in the pathogenesis of nonalcoholic fatty liver disease (NAFLD) remains unclear. To evaluate this, we measured in 207 patients with NAFLD (age = 51 ± 1, body mass index = 34.1 ± 0.3 kg/m(2) ) and 22 controls without NAFLD (no NAFLD) adipose tissue insulin resistance by means of a validated index (Adipo-IR(i) = plasma free fatty acids [FFA] x insulin [FPI] concentration) and as the suppression of plasma FFA during an oral glucose tolerance test and by a low-dose insulin infusion. We also explored the relationship between adipose tissue insulin resistance with metabolic and histological parameters by dividing them based on quartiles of adipose tissue insulin resistance (Adipo-IR(i) quartiles: Q1 = more sensitive; Q4 = more insulin resistant). Hepatic insulin resistance, measured as an index derived from endogenous glucose production x FPI (HIRi), and muscle insulin sensitivity, were assessed during a euglycemic insulin clamp with 3-[(3) H] glucose. Liver fat was measured by magnetic resonance imaging and spectroscopy, and a liver biopsy was performed to assess liver histology. Compared to patients without steatosis, patients with NAFLD were insulin resistant at the level of adipose tissue, liver, and skeletal muscle and had higher plasma aspartate aminotransferase and alanine aminotransferase, triglycerides, and lower high-density lipoprotein cholesterol and adiponectin levels (all P < 0.01). Metabolic parameters, hepatic insulin resistance, and liver fibrosis (but not necroinflammation) deteriorated as quartiles of adipose tissue insulin resistance worsened (all P < 0.01). CONCLUSION: Adipose tissue insulin resistance plays a key role in the development of metabolic and histological abnormalities of obese patients with NAFLD. Treatment strategies targeting adipose tissue insulin resistance (e.g., weight loss and thiazolidinediones) may be of value in this population.

The future of thiazolidinedione therapy in the management of type 2 diabetes mellitus.

Since their approval, thiazolidinediones (TZDs) have been used extensively as insulin-sensitizers for the management of type 2 diabetes mellitus (T2DM). Activation of peroxisomal proliferator-activated receptor gamma (PPARγ) nuclear receptors by TZDs leads to a vast spectrum of metabolic and antiinflammatory effects. In the past decade, clinicians and scientists across the fields of metabolism, diabetes, liver disease (NAFLD), atherosclerosis, inflammation, infertility, and even cancer have had high hopes about the potential for TZDs to treat many of these diseases. However, an increasing awareness about undesirable "off-target" effects of TZDs have made us rethink their role and be more cautious about the long-term benefits and risks related to their use. This review examines the most relevant work on the benefits and risks associated with TZD treatment, with a focus on the only PPARγ agonist currently available (pioglitazone), aiming to offer the reader a balanced overview about the current and future role of TZDs in the management of insulin-resistant states and T2DM.

Approach to the Patient With Nonalcoholic Fatty Liver Disease.

CONTEXT: Nonalcoholic fatty liver disease (NAFLD) is associated with obesity and type 2 diabetes (T2D), causing substantial burden from hepatic and extrahepatic complications. However, endocrinologists often follow people who are at the highest risk of its more severe form with nonalcoholic steatohepatitis or NASH (i.e., T2D or obesity with cardiometabolic risk factors). Endocrinologists are in a unique position to prevent cirrhosis in this population with early diagnosis and treatment. OBJECTIVE: This work aims to offer endocrinologists a practical approach for the management of patients with NAFLD, including diagnosis, fibrosis risk stratification, and referral to hepatologists. PATIENTS: (1) An asymptomatic patient with obesity and cardiometabolic risk factors, found to have hepatic steatosis; (2) a patient with T2D and NASH with clinically significant liver fibrosis; and (3) a liver transplant recipient with a history of NASH cirrhosis, with significant weight regain and with recurrent NAFLD on the transplanted organ. CONCLUSION: NASH can be reversed with proper management of obesity and of T2D. While no agents are currently approved for the treatment of NASH, treatment should include lifestyle changes and a broader use of structured weight-loss programs, obesity pharmacotherapy, and bariatric surgery. Diabetes medications such as pioglitazone and some glucagon-like peptide 1 receptor agonists may also improve liver histology and cardiometabolic health. Sodium-glucose cotransporter-2 inhibitors and insulin may ameliorate steatosis, but their effect on steatohepatitis remains unclear. Awareness by endocrinologists about, establishing an early diagnosis of fibrosis (ie, FIB-4, liver elastography) in patients at high-risk of cirrhosis, long-term monitoring, and timely referral to the hepatologist are all critical to curve the looming epidemic of cirrhosis from NAFLD.

Adipose Tissue Insulin Resistance Predicts the Severity of Liver Fibrosis in Patients With Type 2 Diabetes and NAFLD.

CONTEXT: Although type 2 diabetes (T2D) is a risk factor for liver fibrosis in nonalcoholic fatty liver disease (NAFLD), the specific contribution of insulin resistance (IR) relative to other factors is unknown. OBJECTIVE: Assess the impact on liver fibrosis in NAFLD of adipose tissue (adipose tissue insulin resistance index [adipo-IR]) and liver (Homeostatic Model Assessment of Insulin Resistance [HOMA-IR]) IR in people with T2D and NAFLD. DESIGN: Participants were screened by elastography in the outpatient clinics for hepatic steatosis and fibrosis, including routine metabolites, cytokeratin-18 (a marker of hepatocyte apoptosis/steatohepatitis), and HOMA-IR/adipo-IR. SETTING: University ambulatory care practice. PARTICIPANTS: A total of 483 participants with T2D. INTERVENTION: Screening for steatosis and fibrosis with elastography. MAIN OUTCOME MEASURES: Liver steatosis (controlled attenuation parameter), fibrosis (liver stiffness measurement), and measurements of IR (adipo-IR, HOMA-IR) and fibrosis (cytokeratin-18). RESULTS: Clinically significant liver fibrosis (stage F ≥ 2 = liver stiffness measurement ≥8.0 kPa) was found in 11%, having more features of the metabolic syndrome, lower adiponectin, and higher aspartate aminotransferase (AST), alanine aminotransferase, liver fat, and cytokeratin-18 (P < 0.05-0.01). In multivariable analysis including just clinical variables (model 1), obesity (body mass index [BMI]) had the strongest association with fibrosis (odds ratio, 2.56; CI, 1.87-3.50; P < 0.01). When metabolic measurements and cytokeratin-18 were included (model 2), only BMI, AST, and liver fat remained significant. When fibrosis stage was adjusted for BMI, AST, and steatosis (model 3), only Adipo-IR remained strongly associated with fibrosis (OR, 1.51; CI, 1.05-2.16; P = 0.03), but not BMI, hepatic IR, or steatosis. CONCLUSIONS: These findings pinpoint to the central role of dysfunctional, insulin-resistant adipose tissue to advanced fibrosis in T2D, beyond simply BMI or steatosis. The clinical implication is that targeting adipose tissue should be the priority of treatment in NAFLD.

Role of ethnicity in overweight and obese patients with nonalcoholic steatohepatitis.

UNLABELLED: The role of ethnicity in determining disease severity in nonalcoholic steatohepatitis (NASH) remains unclear. We recruited 152 patients with biopsy-proven NASH, 63% of whom were Hispanic and 37% of whom were Caucasian. Both groups were well matched for age, sex, and total body fat. We measured: (1) liver fat by magnetic resonance imaging and spectroscopy; (2) fasting plasma glucose, fasting plasma insulin (FPI), and free fatty acid (FFA) levels; (3) total body fat by dual energy x-ray absorptiometry (DXA); (4) liver and muscle insulin sensitivity (insulin clamp with 3-[(3)H] glucose); (5) insulin resistance at the level of the liver (fasting endogenous glucose production derived from 3-[(3)H] glucose infusion × FPI) and adipose tissue (fasting FFA × FPI). Liver fat was slightly, but not significantly, higher in Hispanic vs. Caucasian patients (27 ± 2% vs. 24 ± 2%, p = 0.16). However, this trend did not translate into worse liver steatosis, necroinflammation or fibrosis. Patients with NASH had severe hepatic, adipose tissue and muscle insulin resistance versus healthy subjects without NASH nonalcoholic fatty liver disease, but there were no differences between both ethnic groups on these parameters. However, Hispanics versus Caucasians with type 2 diabetes mellitus (T2DM) had a trend for worse hepatic/adipose tissue insulin resistance and fibrosis. CONCLUSION: When Hispanic and Caucasian patients with NASH are well matched for clinical parameters, particularly for adiposity, slightly higher liver fat content is not associated with worse hepatic insulin resistance or more severe NASH on histology. Hispanic ethnicity does not appear to be a major determinant of disease severity in NASH, although those with diabetes may be at greater risk of fibrosis. Given the higher risk of T2DM in Hispanics, long-term studies are needed to define their risk of disease progression.

Assessing strategies to target screening for advanced liver fibrosis among overweight and obese patients.

Aim: The optimal screening strategy for advanced liver fibrosis in overweight and obese patients is unknown. The aim of this study is to compare the performance of different strategies to select patients at high risk of advanced liver fibrosis for screening using non-invasive tools. Methods: All patients underwent: liver 1H-MRS and percutaneous liver biopsy (in those with nonalcoholic fatty liver disease [NAFLD]). Unique selection strategies were compared to determine the best screening algorithm: (A) A "metabolic approach": selecting patients based on HOMA-IR ≥ 3; (B) A "diabetes approach": selecting only patients with type 2 diabetes; (C) An "imaging approach": selecting patients with hepatic steatosis based on 1H-MRS; (D) A "liver biochemistry approach": selecting patients with elevated ALT (i.e., ≥ 30 IU/L for males and ≥ 19 IU/L for females); and (E) Universal screening of overweight and obese patients. FIB-4 index, NAFLD fibrosis score, and APRI were applied as screening strategies. Results: A total of 275 patients were included in the study. Patients with advanced fibrosis (n = 29) were matched for age, gender, ethnicity, and BMI. Selecting patients by ALT elevation provided the most effective strategy, limiting the false positive rate while maintaining the sensitivity compared to universal screening. Selecting patients by any other strategy did not contribute to increasing the sensitivity of the approach and resulted in more false positive results. Conclusion: Universal screening of overweight/obese patients for advanced fibrosis with non-invasive tools is unwarranted, as selection strategies based on elevated ALT levels lead to the same sensitivity with a lower false positive rate (i.e., fewer patients that would require a liver biopsy or referral to hepatology).

Intact Fasting Insulin Identifies Nonalcoholic Fatty Liver Disease in Patients Without Diabetes.

CONTEXT: Patients with nonalcoholic fatty liver disease (NAFLD) are characterized by insulin resistance and hyperinsulinism. However, insulin resistance measurements have not been shown to be good diagnostic tools to predict NAFLD in prior studies. OBJECTIVE: We aimed to assess a newly validated method to measure intact molecules of insulin by mass spectrometry to predict NAFLD. METHODS: Patients underwent a 2-hour oral glucose tolerance test (OGTT), a liver magnetic resonance spectroscopy (1H-MRS), and a percutaneous liver biopsy if they had a diagnosis of NAFLD. Mass spectrometry was used to measure intact molecules of insulin and C-peptide. RESULTS: A total of 180 patients were recruited (67% male; 52 ± 11 years of age; body mass index [BMI] 33.2 ± 5.7 kg/m2; 46% with diabetes and 65% with NAFLD). Intact fasting insulin was higher in patients with NAFLD, irrespective of diabetes status. Patients with NAFLD without diabetes showed ~4-fold increase in insulin secretion during the OGTT compared with all other subgroups (P = 0.008). Fasting intact insulin measurements predicted NAFLD in patients without diabetes (area under the receiver operating characteristic curve [AUC] of 0.90 [0.84-0.96]). This was significantly better than measuring insulin by radioimmunoassay (AUC 0.80 [0.71-0.89]; P = 0.007). Intact fasting insulin was better than other clinical variables (eg, aspartate transaminase, triglycerides, high-density lipoprotein, glucose, HbA1c, and BMI) to predict NAFLD. When combined with alanine transaminase (ALT) (intact insulin × ALT), it detected NAFLD with AUC 0.94 (0.89-0.99) and positive and negative predictive values of 93% and 88%, respectively. This newly described approach was significantly better than previously validated noninvasive scores such as NAFLD-LFS (P = 0.009), HSI (P < 0.001), and TyG index (P = 0.039). CONCLUSION: In patients without diabetes, accurate measurement of fasting intact insulin levels by mass spectrometry constitutes an easy and noninvasive strategy to predict presence of NAFLD.

Advanced Liver Fibrosis Is Common in Patients With Type 2 Diabetes Followed in the Outpatient Setting: The Need for Systematic Screening.

OBJECTIVE: Assess the prevalence of nonalcoholic fatty liver disease (NAFLD) and of liver fibrosis associated with nonalcoholic steatohepatitis in unselected patients with type 2 diabetes mellitus (T2DM). RESEARCH DESIGN AND METHODS: A total of 561 patients with T2DM (age: 60 ± 11 years; BMI: 33.4 ± 6.2 kg/m2; and HbA1c: 7.5 ± 1.8%) attending primary care or endocrinology outpatient clinics and unaware of having NAFLD were recruited. At the visit, volunteers were invited to be screened by elastography for steatosis and fibrosis by controlled attenuation parameter (≥274 dB/m) and liver stiffness measurement (LSM; ≥7.0 kPa), respectively. Secondary causes of liver disease were ruled out. Diagnostic panels for prediction of advanced fibrosis, such as AST-to-platelet ratio index (APRI) and Fibrosis-4 (FIB-4) index, were also measured. A liver biopsy was performed if results were suggestive of fibrosis. RESULTS: The prevalence of steatosis was 70% and of fibrosis 21% (LSM ≥7.0 kPa). Moderate fibrosis (F2: LSM ≥8.2 kPa) was present in 6% and severe fibrosis or cirrhosis (F3-4: LSM ≥9.7 kPa) in 9%, similar to that estimated by FIB-4 and APRI panels. Noninvasive testing was consistent with liver biopsy results. Elevated AST or ALT ≥40 units/L was present in a minority of patients with steatosis (8% and 13%, respectively) or with liver fibrosis (18% and 28%, respectively). This suggests that AST/ALT alone are insufficient as initial screening. However, performance may be enhanced by imaging (e.g., transient elastography) and plasma diagnostic panels (e.g., FIB-4 and APRI). CONCLUSIONS: Moderate-to-advanced fibrosis (F2 or higher), an established risk factor for cirrhosis and overall mortality, affects at least one out of six (15%) patients with T2DM. These results support the American Diabetes Association guidelines to screen for clinically significant fibrosis in patients with T2DM with steatosis or elevated ALT.

Effect of pioglitazone on bone mineral density in patients with nonalcoholic steatohepatitis: A 36-month clinical trial.

BACKGROUND: The effects of pioglitazone on bone metabolism are unclear. This study evaluated the long-term effects of pioglitazone on bone mineral density (BMD) and bone metabolism in patients with prediabetes or type 2 diabetes mellitus (T2DM) and non-alcoholic steatohepatitis (NASH). METHODS: Ninety-two patients with prediabetes or T2DM and biopsy-proven NASH with BMD and baseline biochemical bone measurements were included. Patients (mean [±SEM] age 51 ± 1 years, 71% male, mean body mass index 34.5 ± 0.5 kg/m2 ) were randomly assigned to pioglitazone (45 mg/day) or placebo for 18 months, followed by an 18-month open-label pioglitazone treatment phase. Baseline, 18- and 36-month evaluations included plasma vitamin D and bone turnover biomarker levels, and BMD measurements at the spine, femoral neck, total hip, and one-third radius. RESULTS: After 18 months of pioglitazone treatment, there were no differences in BMD versus placebo at either the femoral neck (P =0.87), total hip (P =0.78), or one-third radius (P =0.44); however, bone density decreased at the level of the spine with pioglitazone (-3.5%; P =0.002). During the extension phase (18-36 months), patients had no further decreases in BMD or plasma biomarkers of bone turnover during pioglitazone treatment. No patient experienced a low-energy bone fracture. CONCLUSIONS: Treatment of patients with prediabetes or T2DM with pioglitazone for up to 3 years was associated with decreased BMD at the level of the lumbar spine. This reduction in BMD at the lumbar spine at 18 months versus placebo suggests an early deleterious effect of pioglitazone on bone metabolism.

Role of Vitamin E for Nonalcoholic Steatohepatitis in Patients With Type 2 Diabetes: A Randomized Controlled Trial.

OBJECTIVE: While vitamin E has shown to improve nonalcoholic steatohepatitis (NASH) in patients without diabetes, information on patients with type 2 diabetes mellitus (T2DM) is lacking. The aim of this study was to determine whether vitamin E, alone or combined with pioglitazone, improves histology in patients with T2DM and NASH. RESEARCH DESIGN AND METHODS: This was a proof-of-concept, randomized, double-blind, placebo-controlled trial conducted from 2010 to 2016. Patients with T2DM and biopsy-proven NASH (n = 105) were randomized to vitamin E 400 IU b.i.d., vitamin E 400 IU b.i.d. plus pioglitazone 45 mg/day, or placebo. Eighty-six patients completed the 18-month study. The primary end point was a two-point reduction in the nonalcoholic fatty liver disease activity score from two different parameters, without worsening of fibrosis. Secondary outcomes were resolution of NASH without worsening of fibrosis, individual histological scores, and metabolic parameters. RESULTS: More patients on combination therapy achieved the primary outcome versus placebo (54% vs. 19%, P = 0.003) but not with vitamin E alone (31% vs. 19%, P = 0.26). Both groups showed improvements in resolution of NASH compared with placebo (combination group: 43% vs. 12%, P = 0.005; vitamin E alone: 33% vs. 12%, P = 0.04). While steatosis assessed by histology improved with combination therapy (P < 0.001) and vitamin E alone (P = 0.018), inflammation (P = 0.018) and ballooning (P = 0.022) only improved with combination therapy. No improvement in fibrosis was observed in any group. CONCLUSIONS: In this proof-of-concept study, combination therapy was better than placebo in improving liver histology in patients with NASH and T2DM. Vitamin E alone did not significantly change the primary histological outcome.