Impacts of the development of acute-on-chronic liver failure and bacterial infections on β-cell function and glucose homeostasis in patients with liver cirrhosis

BACKGROUND

The pathogenesis involved in glucose metabolism disorders (GMDs) in patients with liver cirrhosis remains unclear.

AIMS

We investigated the effects of acute-on-chronic liver failure (ACLF) development and bacterial infections (BIs) on pancreatic β-cell function and glucose homeostasis in individuals with liver cirrhosis.

METHODS

A retrospective analysis was conducted on 327 patients experiencing acute deterioration of liver cirrhosis. Oral glucose tolerance tests (OGTTs) and OGTT-based β-cell function indices were employed to assess β-cell function and glucose homeostasis. Univariate and multivariate logistic regression analyses were employed to identify GMD-associated risk factors.

RESULTS

Both the development of ACLF and BIs significantly increased the prevalence of GMDs. Both ACLF and BIs markedly elevated the homeostasis model of assessment 2-insulin resistance (HOMA2-IR). ACLF significantly impaired glucose-stimulated insulin secretion, as evidenced by reduced insulinogenic index (IGI). Patients with GMDs exhibited significantly lower IGI levels than those without GMDs. Independent risk factors associated with GMDs were prothrombin activity (odds ratio [OR]=0.981, 95% confidence interval [CI]: 0.960-0.995), HOMA2-IR (OR=1.749, 95% CI: 1.130-2.707), and IGI (OR=0.963, 95% CI: 0.947-0.978).

CONCLUSIONS

In liver cirrhosis, the onset of ACLF impairs glucose-stimulated insulin secretion from β-cells. Both liver impairment and BIs contribute to increased insulin resistance, ultimately disturbing glucose homeostasis.

The declining insulinogenic index correlates with inflammation and metabolic dysregulation in non-obese individuals assessed by blood gene expression

AIMS

Diabetes onset is difficult to predict. Since decreased insulinogenic index (IGI) is observed in prediabetes, and blood gene expression correlates with insulin secretion, candidate biomarkers can be identified.

METHODS

We collected blood from 96 participants (54 males, 42 females) in 2008 (age: 52.5 years) and 2016 for clinical and gene expression analyses. IGI was derived from values of insulin and glucose at fasting and at 30 min post-OGTT. Two subgroups were identified based on IGI variation: "Minor change in IGI" group with absolute value variation between -0.05 and +0.05, and "Decrease in IGI" group with a variation between -20 and -0.05.

RESULTS

Following the comparison of "Minor change in IGI" and "Decrease in IGI" groups at time 0 (2008), we identified 77 genes correlating with declining IGI, related to response to lipid, carbohydrate, and hormone metabolism, response to stress and DNA metabolic processes. Over the eight years, genes correlating to declining IGI were related to inflammation, metabolic and hormonal dysregulation. Individuals with minor change in IGI, instead, featured homeostatic and regenerative responses.

CONCLUSIONS

By blood gene expression analysis of non-obese individuals, we identified potential gene biomarkers correlating to declining IGI, associated to a pathophysiology of inflammation and metabolic dysregulation.

Insulinogenic index and early phase insulin secretion predict increased risk of worsening glucose tolerance and of cystic fibrosis-related diabetes

OBJECTIVE

Measures of stimulated insulin secretion are emerging as important predictors of diabetes mellitus in at-risk populations. We analyzed the utility of clinical estimates of insulin secretion in a prospective cohort at risk for cystic fibrosis-related diabetes (CFRD).

METHODS

We divided the profiles of 189 people with CF (pwCF) followed longitudinally in the Montreal CF cohort (mean follow up 6.6 ± 1.2 years) according to quartiles of the insulinogenic index (IGI; (I₃₀-I₀)/(G₃₀-G₀)); area under the curve for insulin normalized for glucose (AUC_ins/glu), and HOMA-B at baseline to compare clinical characteristics and risk of CFRD according to quartiles for each measure. We also compared characteristics of 40 pwCF found to have de novo CFRD at baseline.

RESULTS

At baseline, IGI and AUC_ins/glu were lower in subjects with de novo CFRD and those who later developed CFRD than those who never developed CFRD (p < 0.0001 for each). Subjects with the lowest quartiles of IGI, AUC_ins/glu, and AUC_{ins/glu 0-30} had increased risk of developing CFRD by Kaplan-Meier analysis (p = 0.0244, p = 0.0024, and p = 0.0338, respectively). There was no significant difference in risk between quartiles of HOMA-B. Subjects in the lowest quartile of IGI showed a significant increase in 2-hour OGTT glucose and AUC_glu between the initial and final study visits (p = 0.0027 and p = 0.0044, respectively).

CONCLUSION

IGI is easily measured in a clinical setting and needs to be validated in prospective studies as a potential tool to improve risk stratification in CFRD with direct relevance to pathogenesis.

Bihormonal dysregulation of insulin and glucagon contributes to glucose intolerance development at one year post-delivery in women with gestational diabetes: a prospective cohort study using an early postpartum 75-g glucose tolerance test

Gestational diabetes mellitus (GDM) is known to be a significant risk factor for the future development of type 2 diabetes. Here, we investigated whether a precise evaluation of β- and α-cell functions helps to identify women at high risk of developing glucose intolerance after GDM. Fifty-six women with GDM underwent a 75-g oral glucose tolerance test (OGTT) at early (6-12 weeks) postpartum. We measured their concentrations of glucose, insulin, proinsulin and glucagon at fasting and 30, 60 and 120 min. At 1-year post-delivery, we classified the women into a normal glucose tolerance (NGT) group or an impaired glucose tolerance (IGT)/diabetes mellitus (DM) group. Forty-three of the 56 women completed the study. At 1-year post-delivery, 17 women had developed IGT/DM and 26 women showed NGT. In the early-postpartum OGTTs, the IGT/DM group showed a lower insulinogenic index, a less glucagon suppression evaluated by the change from fasting to 30 min (ΔGlucagon 30 min), and a higher glucagon-to-insulin ratio at 30 min compared to the NGT group. There were no significant between-group differences in proinsulin levels or proinsulin-to-insulin ratios. Insulinogenic index <0.6 and ΔGlucagon 30 min >0 pg/mL were identified as predictors for the development of IGT/DM after GDM, independent of age, body mass index, and lactation intensity. These results suggest that the bihormonal disorder of insulin and glucagon causes the postpartum development of glucose intolerance. The measurement of plasma insulin and glucagon during the initial OGTT at early postpartum period can help to make optimal decisions regarding the postpartum management of women with GDM.

Characteristics associated with elevated 1-h plasma glucose levels during a 75-g oral glucose tolerance test in non-obese Japanese men

Elevated 1-h plasma glucose (1h-PG; ≥155 mg/dL) during an oral glucose tolerance test is a risk factor for type 2 diabetes. However, the metabolic characteristics of non-obese Asians with elevated 1h-PG are unknown. Thus, we studied 59 non-obese Japanese men with normal glucose tolerance. We divided study participants into the Low 1h-PG group (<155 mg/dL) and the High 1h-PG group (≥155 mg/dL). We compared the metabolic characteristics of the groups, including tissue-specific insulin sensitivity measured using a two-step hyperinsulinemic-euglycemic clamp. Insulinogenic index and adiponectin levels were significantly lower in the High 1h-PG group than in the Low 1h-PG group. Other characteristics, including insulin sensitivity, adiposity and ectopic fat accumulation, were similar between the groups. In conclusion, non-obese Japanese men with high 1h-PG have impaired early-phase insulin secretion and lower adiponectin levels. Insulin resistance and abnormal fat distribution were not evident in this population.

The GLP-1 response to glucose does not mediate beta and alpha cell dysfunction in Hispanics with abnormal glucose metabolism

AIMS

Glucagon-like peptide-1 (GLP-1) contributes to insulin secretion after meals. Though Hispanics have increased risk for type 2 diabetes mellitus, it is unknown if impaired GLP-1 secretion contributes to this risk. We therefore studied plasma GLP-1 secretion and action in Hispanic adults.

METHODS

Hispanic (H; n = 31) and non-Hispanic (nH; n = 15) participants underwent an oral glucose tolerance test (OGTT). All participants were categorized by glucose tolerance into four groups: normal glucose tolerant non-Hispanic (NGT-nH; n = 15), normal glucose tolerant Hispanic (NGT-H; n = 12), impaired glucose tolerant Hispanic (IGT-H; n = 11), or newly diagnosed type 2 diabetes mellitus, Hispanic (T2D-H; n = 8).

RESULTS

Glucose-induced increments in plasma GLP-1 (Δ-GLP-1) were not different in NGT-H and NGT-nH (p = .38), nor amongst Hispanic subgroups with varying degrees of glucose homeostasis (p = .6). In contrast, the insulinogenic index in T2D-H group was lower than the other groups (p = .016). Subjects with abnormal glucose homeostasis (AGH), i.e., T2D-H plus IGT-H, had a diminished glucagon suppression index compared to patients with normal glucose homeostasis (NGT-H plus NGT-nH) (p = .035).

CONCLUSIONS

GLP-1 responses to glucose were similar in Hispanic and Non-Hispanic NGT. Despite similar glucose-induced Δ-GLP-1, insulin and glucagon responses were abnormal in T2D-H and AGH, respectively. Thus, impaired GLP-1 secretion is unlikely to play a role in islet dysfunction in T2D. Although GLP-1 therapeutics enhance insulin secretion and glucagon suppression, it is likely due to pharmacological amplification of the GLP-1 pathways rather than treatment of hormonal deficiency.

Investigation of the relationship between hemoglobin and serum iron levels and early-phase insulin secretion in non-diabetic subjects

AIMS

Recent biological and epidemiological studies have found that insulin resistance is linked to iron overload. However, little is known about the association between hemoglobin and/or serum iron levels and pancreatic β-cell function. In this gender-separated cross-sectional study, we aimed to investigate the association of hemoglobin and serum iron levels with early-phase insulin secretion in non-diabetic subjects.

METHODS

A total of 804 non-diabetic Japanese subjects (482 males and 322 females) aged over 30 years old were enrolled in the study. Early-phase insulin secretion was estimated using the insulinogenic index (IGI [ΔInsulin(30-0 min)/ΔGlucose(30-0 min)]) during a 75-g oral glucose tolerance test.

RESULTS

Simple linear regression analysis showed that IGI negatively correlated with hemoglobin levels in male but not in female subjects. However, IGI did not correlate with serum iron levels in either gender. Multivariate linear regression analysis in male subjects revealed that hemoglobin levels were predictors of IGI, responsible for 3.0 % of IGI variation (P = 0.008). The association was independent of age, BMI, fasting glucose and insulin levels, and lipid profiles. In non-diabetic Japanese males, hemoglobin levels significantly and negatively correlated with early-phase insulin secretion.

CONCLUSIONS

Our finding suggests that elevated hemoglobin levels may have a gender-specific impact on β-cell function and could be an independent predictor of β-cell dysfunction.

Risk factors associated with abnormal glucose tolerance in the early postpartum period among Japanese women with gestational diabetes

OBJECTIVE

To identify the risk factors associated with abnormal glucose tolerance (AGT) on the first postpartum oral glucose tolerance test (OGTT) among Japanese women with gestational diabetes (GDM).

METHODS

In a retrospective study, data were analyzed from women with GDM who underwent their first postpartum OGTT 6-8weeks post partum at a center in Omura, Japan, between January 1, 2007, and December 31, 2011. Women with diabetes or impaired glucose tolerance were deemed to have postpartum AGT. The association between postpartum AGT and various risk factors was analyzed.

RESULTS

Among 169 women who underwent a postpartum OGTT, 58 (34.3%) had AGT. The significant risk factors associated with postpartum AGT in univariate analysis were pre-pregnancy body mass index (P=0.096), 1-hour plasma glucose (P=0.006), hemoglobin A1c (P<0.001), insulinogenic index (P=0.05), an insulinogenic index of less than 0.4 (P=0.006), and insulin therapy during pregnancy (P<0.001). Independent risk factors identified by multivariate logistic regression models were insulinogenic index (odds ratio [OR] 0.10, 95% confidence interval [CI] 0.01-0.74; P=0.002), an insulinogenic index of less than 0.4 (OR 5.70, 95% CI 1.69-21.66; P=0.005), and insulin therapy during pregnancy (OR 3.43, 95% CI 1.03-12.55; P=0.044).

CONCLUSION

Among Japanese women with GDM, a lower insulinogenic index and use of insulin therapy during pregnancy are associated with early postpartum AGT.