The evolution of non-diabetic hyperglycemia: a longitudinal study

Association between Subclinical Hypothyroidism and Glycemic Control in Older Adults in a Medical Center in Peru

Objective

To determine whether there is an association between subclinical hypothyroidism and glycemic control in older adults who received care at the "Centro Médico Naval" from 2010 to 2015.

Methods

This retrospective analytical study analyzed a secondary database of the care of elderly in the study hospital. The sample was comprised of 1,385 older adults. To detect an association between variables, the Poisson regression with robust variance was used at a significance level of 95%. The analyses were carried out with the STATA 16 program.

Results

Of the elderly 45.6% were between 71 and 80 years old; 58.4% were women and 43.8% had a normal body mass index. There was evidence of inadequate glycemic control in 8.1% and subclinical hypothyroidism in 15.2% of the elderly patients. Subclinical hypothyroidism was more frequent in the inadequate glycemic control vs. adequate glycemic control populations (41.1% vs. 13.0%). In the multivariance analysis, subclinical hypothyroidism (aPR = 2.22 95% CI [1.47-3.36]) was independent factor associated with inadequate glycemic control (p < 0.001).

Conclusions

A significant association was detected between subclinical hypothyroidism and inadequate glycemic control in older adults who presented at the "Centro Médico Naval" from 2010 to 2015.

Modifiable predictors of type 2 diabetes mellitus and roles of insulin resistance and β-cell function over a 6-year study and 30-year follow-up

PURPOSE

This study aimed to examine the modifiable predictors of T2DM and the roles of insulin resistance (IR) and β-cell function over a 6-year study and 30-year follow-up.

METHODS

A total of 462 non-diabetic participants, 282 with impaired glucose tolerance (IGT), and 180 with normal glucose tolerance (NGT) were enrolled in this analysis. The Matsuda IR index and area under the curve of insulin-to-glucose ratio (AUCI/G-R) were used as IR and β-cell function indices in the analysis.

RESULTS

In all participants, multivariable analysis showed that BMI, glucose status, Matsuda IR index and systolic blood pressure (SBP) at baseline were independently associated with an increased risk of T2DM over 30 years, whereas lifestyle intervention and AUCI/G-R were inversely associated with this risk. The predictive effect of the Matsuda IR index and AUCI/G-R in participants with IGT was consistent with the results of all participants, whereas in those with NGT, only the Matsuda IR index, not the AUCI/G-R, predicted the development of T2DM (HR = 1.42, 95% CI 1.07-1.89 vs HR = 1.09, 95% CI 0.76-1.56). The predictive effect of the Matsuda IR index on T2DM existed even in participants with BMI < 25 (p = 0.049).

CONCLUSION

The modifiable predictors of T2DM in Chinese adults were high BMI, hypertension, mild hyperglycaemia, IR, and β-cell dysfunction. Both IR and β-cell function contributed to the development of T2DM in the long term; however, IR remains the initial and long-standing key risk factor for T2DM.

Hepatic Steatosis and High-normal Fasting Glucose as Risk Factors for Incident Prediabetes

Context

The role of hepatic steatosis (HS) in the initial stages of developing type 2 diabetes remains unclear.

Objective

We aimed to clarify the impact of HS indexed by Fatty Liver Index (FLI) and high-normal fasting plasma glucose (FPG) as risk factors for incident prediabetes in a nonobese cohort.

Methods

Data from 1125 participants with ADA-defined normal glucose metabolism (median age 52 years; BMI 23.1 kg/m²) were used for retrospective analysis. In the entire population, correlation between normal FPG and FLI was evaluated by multiple regression adjusted for age and sex. Follow-up data from 599 participants in whom 75-g OGTT was repeated 3.7 years later showed that 169 developed prediabetes. This was analyzed by the multivariate Cox proportional hazards model.

Results

In the entire population, FLI was positively correlated with FPG (P < 0.01): mean FLI increased from 15.8 at FPG 4.2 mmol/L to 31.6 at FPG 5.5 mmol/L. Analysis of the 599 participants (2061 person-years) by Cox model, adjusted for sex, age, family history of diabetes, ISI_MATSUDA, and Stumvoll-1, clarified an increased risk of prediabetes with high-normal FPG and FLI. Risk was increased 2.2 times with FLI ≥ 16.5 vs FLI < 16.5, P < 0.001, and increased 2.1 times in participants with FPG ≥ 5.3 mmol/L, P < 0.001. Cutoff values (unadjusted) were obtained by ROC at the point of the largest Youden’s index using the entire range of the variables.

Conclusion

Even among nonobese individuals, HS indexed by FLI and a high-normal FPG (≥ 5.3 mmol/L) are risk factors for prediabetes, independently from insulin.

Insulin resistance increases the risk of incident type 2 diabetes mellitus in patients with non-alcoholic fatty liver disease

AIM

Type 2 diabetes mellitus (T2DM) is a major complication of patients with non-alcoholic fatty liver disease (NAFLD). The aim of this retrospective study is to determine the risk factors for development of T2DM in patients with biopsy-proven NAFLD.

METHODS

One hundred and sixty two consecutive patients with biopsy-proven NAFLD who received a 75-g oral glucose tolerance test were enrolled as the total cohort. Among them, we analyzed 89 patients without T2DM diagnosed by oral glucose tolerance test to estimate the cumulative rate for development of T2DM as the follow-up cohort.

RESULTS

Of 162 patients, the glucose tolerance pattern were DM in 45 patients (27.8%), impaired glucose tolerance in 68 (42.0%), and normal glucose tolerance in 49 (30.2%). Patients with NAFL tended to be more likely to have normal glucose tolerance than those with non-alcoholic steatohepatitis (NASH). The serum levels of pre- and post-load insulin were significantly higher in the NASH group. Of 89 patients without T2DM, 13 patients newly developed T2DM during a follow-up period of 5.2 years. The cumulative rate of T2DM incidence was 8.8% at the end of the 5th year and 23.4% at the end of the 10th year. Multivariate analysis identified homeostasis model of assessment - insulin resistance (≥3.85, hazard ratio 40.1, P = 0.033) as an independent risk factor for development of T2DM.

CONCLUSIONS

Patients with NASH have an underlying potential of glucose intolerance. In NAFLD patients, insulin resistance is the most important risk factor for the incidence of T2DM. Appropriate therapy against insulin resistance could be needed for patients with NAFLD to prevent development of T2DM.

Relationship of hyperinsulinaemia, insulin resistance and β-cell dysfunction with incident diabetes and pre-diabetes: the Tehran Lipid and Glucose Study

AIMS

To examine the association of fasting insulin, insulin resistance and reduced β-cell function with incident Type 2 diabetes and pre-diabetes (isolated impaired fasting glucose/isolated impaired glucose tolerance and combined impaired fasting glucose/impaired glucose tolerance).

METHODS

An Iranian population comprising 1532 men and 2221 women, aged ≥ 20 years, with normal fasting glucose and normal glucose tolerance at baseline, were enrolled in the study. Multivariable Cox proportional hazard models were used to calculate the hazard ratios and 95% CIs of fasting insulin, updated homeostasis model assessments of insulin resistance and β-cell function for incident Type 2 diabetes, isolated impaired fasting glucose, isolated impaired glucose tolerance and combined impaired fasting glucose/impaired glucose tolerance.

RESULTS

During a median follow-up of 9.2 years, the annual incidence rates (95% CI) of diabetes were 3.73 (2.74-4.94) and 4.06 (3.21-5.06) per 1000 person-years in men and women, respectively. In both men and women, fasting insulin and homeostasis model assessment of insulin resistance (≥ 75th percentile) were significantly associated with incident diabetes and combined impaired fasting glucose/impaired glucose tolerance; however, reduced β-cell function as measured by homeostasis model assessment of β-cell function (< 25th percentile) was associated with incident isolated impaired fasting glucose solely in men [hazard ratio 1.35 (95% CI 1.02-1.78)] in multivariable analysis including waist-hip ratio). Hyperinsulinaemia, insulin resistance and β-cell dysfunction were not related to the incidence of isolated impaired glucose tolerance in either gender.

CONCLUSIONS

Fasting hyperinsulinaemia and insulin resistance were strong risk factors for progression to diabetes and combined impaired fasting glucose/impaired glucose tolerance in a population with normal fasting glucose/normal glucose tolerance. In addition, impaired β-cell function at baseline was related to the development of isolated impaired fasting glucose only in men and, in both men and women, neither insulin resistance nor β-cell dysfunction were associated with incident isolated impaired glucose tolerance.

Longitudinal changes in insulin sensitivity, insulin secretion, beta cell function and glucose effectiveness during development of non-diabetic hyperglycemia in a Japanese population

Since there had been no previous studies of alterations in insulin sensitivity, glucose-stimulated insulin secretion, beta cell function and glucose effectiveness during the development of non-diabetic hyperglycemia in Asian populations, we conducted a longitudinal study of such changes in 244 Japanese adults with normal glucose tolerance (median BMI 23.3 kg/m² and age 51 yrs). The median follow-up period was 3.3 yrs. One hundred and eighty-two subjects maintained normal glucose tolerance (nonprogressors). After excluding the 3 subjects who progressed to diabetes, we analyzed the 59 who developed non-diabetic hyperglycemia (progressors), of which 31 progressed to impaired fasting glucose and 28 to impaired glucose tolerance. Whole body insulin sensitivity was estimated by ISI_Matsuda, glucose-stimulated insulin secretion by [δIRI_0-30/δPG_0-30] and Stumvoll indices, hepatic insulin sensitivity by quantitative insulin sensitivity check index (QUICKI) and 1/fasting IRI, beta cell function by oral disposition index (DI_O) ([δIRI_0-30/δPG_0-30]∙[ISI_Matsuda]), and glucose effectiveness by an OGTT-derived index (SgI_O). ISI_Matsuda (p <0.05), [δIRI_0-30/δPG_0-30], DI_O and SgI_O (both p <0.01), but not QUICKI, 1/fasting IRI, or Stumvoll-1st and -2nd phases, were lower in the progressors at baseline. This group was also characterized by the following: 1) ISI_Matsuda, DI_O and SgI_O were reduced by 34%, 32% and 11%, respectively (all p <0.01); 2) QUICKI and 1/fasting IRI diminished by 21% and 5%, respectively (both p <0.01); and 3) no significant changes were found in [δIRI_0-30/δPG_0-30], Stumvoll-1st and -2nd phases or BMI during the follow-up. In the nonprogressors, no indices changed significantly during the follow-up. Our study concluded that during the transition from normal glucose tolerance to non-diabetic hyperglycemia in this non-obese population, whole body insulin sensitivity, hepatic insulin sensitivity, beta cell function, and glucose effectiveness were all attenuated, but no significant changes in glucose-stimulated insulin secretion occurred. Also of note is the fact that the transition took place without any accompanying increase in BMI.