Impact of treatment with saxagliptin on glycaemic stability and β-cell function in the SAVOR-TIMI 53 study

AIMS

To study the effects of saxagliptin, a dipeptidyl peptidase-4 inhibitor, on glycaemic stability and β-cell function in the SAVOR-TIMI 53 trial.

METHODS

We randomized 16,492 patients with type 2 diabetes (T2D) to saxagliptin or placebo, added to current antidiabetic medications, and followed them for a median of 2.1 years. Glycaemic instability was defined by: (i) a glycated haemoglobin (HbA1c) increase of ≥ 0.5% post-randomization; (ii) the initiation of new antidiabetic medications for ≥ 3 months; or (iii) an increase in dose of oral antidiabetic medication or ≥ 25% increase in insulin dose for ≥ 3 months. β-cell function was assessed according to fasting homeostatic model 2 assessment of β-cell function (HOMA-2β) values at baseline and at year 2 in patients not treated with insulin.

RESULTS

Compared with placebo, participants treated with saxagliptin had a reduction in the development of glycaemic instability (hazard ratio 0.71; 95% confidence interval 0.68-0.74; p < 0.0001). In participants treated with saxagliptin compared with placebo, the occurrence of an HbA1c increase of ≥ 0.5% was reduced by 35.2%; initiation of insulin was decreased by 31.7% and the increases in doses of an oral antidiabetic drug or insulin were reduced by 19.5 and 23.5%, respectively (all p < 0.0001). At 2 years, HOMA-2β values decreased by 4.9% in participants treated with placebo, compared with an increase of 1.1% in those treated with saxagliptin (p < 0.0001).

CONCLUSIONS

Saxagliptin improved glycaemia and prevented the reduction in HOMA-2β values. Saxagliptin may reduce the usual decline in β-cell function in T2D, thereby slowing diabetes progression.

Hypoglycaemic episodes and risk of dementia in diabetes mellitus: 7-year follow-up study

OBJECTIVE

We investigated the risk of dementia in patients with type 2 diabetes with or without prior hypoglycaemic episodes.

SUBJECTS AND SETTING

One million subjects randomly selected from the National Health Insurance Research Database, Taiwan.

RESULTS

A total of 15 404 diabetic subjects without prior dementia and a mean age of 64.2 years were enrolled in the study. About 2% (n = 289) of participants had at least one episode of hypoglycaemia in a 3-year period; these subjects were older and more likely to be women and also had higher rates of insulin use and comorbidities compared to those without hypoglycaemia. During a total of 7 years of follow-up (mean and median follow-up, 3.8 and 4.8 years, respectively), 1106 patients with diabetes (7.2%) developed dementia. The incidence rate of dementia was higher in diabetic subjects with [29.9 per 1000 person-years (95% CI 22.1-39.2)] compared to those without [11.1 per 1000 person-years (95% CI 10.3-11.8)] hypoglycaemic episodes. The crude rate ratio (RR) and age- and gender-adjusted RR values for dementia were 2.76 (95% CI 2.06-3.70, P < 0.001) and 1.60 (95% CI 1.19-2.14, P = 0.002), respectively, in diabetic subjects with hypoglycaemia compared to those without hypoglycaemia. Results of Cox proportional hazards analysis revealed that hypoglycaemia, older age, female gender and insulin use were independent predictors of dementia.

CONCLUSION

Adult diabetic patients with prior hypoglycaemia had a significantly increased risk of dementia. The influence of hypoglycaemic episodes on brain function warrants further investigation.

Type 2 diabetes prevalence and incidence among adults in Taiwan during 1999-2004: a national health insurance data set study

AIM

To evaluate annual prevalence and incidence of Type 2 diabetes and to examine possible trends among adults in Taiwan.

METHODS

A retrospective nationwide longitudinal study using the Taiwan National Health Insurance Research Database collected during 1999-2004. Adult patients aged > or = 20 years old with prevalent and incident Type 2 diabetes were identified using ICD-9-CM diagnostic codes. Age-specific and age-direct-standardized annual incidence and prevalence were calculated to describe their trends in different gender and age group and compared using Poisson regression.

RESULTS

During the study years, the age-standardized prevalence of Type 2 diabetes increased from 4.7 to 6.5% for men and from 5.3 to 6.6% for women. The increasing trends in prevalence were significant and higher among people aged < 40 and > or = 80 years. The age-standardized incidence rates of Type 2 diabetes per 1000 person-years were approximately 7.6 and remain stable for men, but decreasing from 7.7 to 6.9 for women. However, the incidence increased significantly in younger adults aged < 40 years whose relative incidence (RI with 95% confidence interval) was 1.31 (1.20-1.42) for men and 1.04 (1.01-1.08) for women. The incidence trends for people aged > or = 40 years were decreased for men and women. The differences in incidence trends between age groups and between genders were all statistically significant (all P < 0.001).

CONCLUSIONS

This study demonstrated a substantial increasing trend in Type 2 diabetes prevalence during 1999-2004 among adults in Taiwan. Despite the incidence decreased in older people, young men aged 20-40 years were most susceptible to higher incidence of Type 2 diabetes.

Use of therapeutic responses to glucose replacement to predict glucose patterns in diabetic patients presenting with severe hypoglycaemia

OBJECTIVE

The purpose of this study was to determine whether initial serum glucose levels, therapeutic responses to intravenous glucose replacement and changes in serum glucose levels over time could predict serum glucose patterns.

METHODS

The patients enrolled in this retrospective chart review had been previously diagnosed with diabetes mellitus and were later hospitalised for severe hypoglycaemia (SH). They were all admitted to the emergency department (ED) during a 4-year period between January 2003 and December 2006. Comparison of the therapeutic responses to glucose replacement according to the serum glucose patterns [categorised into recurrent hypoglycaemia (RH), overshoot hyperglycaemia (OH) and favourable groups] during the first 48 h was performed.

RESULTS

Compared with the favourable group, therapeutic responses to glucose replacement were significantly lower in the RH group and higher in the OH group; the changes in serum glucose levels over time were also significantly lower in the RH group and higher in the OH group.

CONCLUSION

Therapeutic responses to glucose replacement and changes in serum glucose levels over time can differentiate diabetic patients with RH and OH from those with favourable glucose patterns during the first 48 h after presentation in the ED with SH. We believe that a 'response-to-treatment' based strategy is useful in determining the ED disposition of diabetic patients presenting with SH.

Effect of cranberry extracts on lipid profiles in subjects with Type 2 diabetes

AIM

To examine the effect of cranberry ingestion on lipid profiles in Type 2 diabetic patients taking oral glucose-lowering drugs.

METHODS

Thirty Type 2 diabetic subjects (16 males and 14 females; mean age 65 +/- 1 years) who were taking oral glucose-lowering medication regularly were enrolled in this randomized, placebo-controlled, double-blind study. Changes in lipid profiles, oxidized low-density lipoprotein (ox-LDL), glycaemic control, components of the metabolic syndrome, C-reactive protein (CRP) and urinary albumin excretion (UAE) were assessed after cranberry or placebo treatment for 12 weeks.

RESULTS

Low-density lipoprotein (LDL) cholesterol decreased significantly in the cranberry group (from 3.3 +/- 0.2 to 2.9 +/- 0.2 mmol/l, P = 0.005) and the decrease was significantly greater than that in the placebo group (-0.4 +/- 0.1 vs. 0.2 +/- 0.1 mmol/l, P < 0.001). Total cholesterol and total : high-density lipoprotein (HDL) cholesterol ratio also decreased significantly (P = 0.020 and 0.044, respectively) in the cranberry group and the reductions were significantly different from those in the placebo group (P < 0.001 and P = 0.032, respectively). However, ox-LDL levels did not change significantly in response to cranberry consumption. Neither fasting glucose nor glycated haemoglobin improved in either group. Changes in components of the metabolic syndrome, UAE and CRP were not significantly different between groups.

CONCLUSIONS

Cranberry supplements are effective in reducing atherosclerotic cholesterol profiles, including LDL cholesterol and total cholesterol levels, as well as total : HDL cholesterol ratio, and have a neutral effect on glycaemic control in Type 2 diabetic subjects taking oral glucose-lowering agents.

Serum testosterone level and related metabolic factors in men over 70 years old

BACKGROUND

Sex hormone decline remarkably decreases metabolic function in elderly men. Many degenerative diseases may relate to testosterone deficiency.

OBJECTIVE

To evaluate the serum testosterone concentration in elderly men, its related metabolic and inflammatory factors, and the relationship of metabolic syndrome to testosterone levels.

METHODS

381 elderly men (78.8+/-4.1 yr old) residing in a veterans' nursing home were enrolled. We measured body height and weight, waist and hip circumferences, body fat, blood pressure, blood glucose and insulin, glycosylated hemoglobin (HbA1c), lipid profile, complete blood count, high sensitivity C-reactive protein (hsCRP), total testosterone, and SHBG. Free testosterone was calculated by Nanjee-Wheeler's method.

RESULTS

Serum total testosterone levels were 0.20-15.74 ng/ml (free testosterone 11.78-478.31 pmol/l). Total testosterone correlated negatively with body mass index (BMI), waist-hip ratio, body fat, blood glucose, blood insulin, HbA1c, serum triglyceride, white blood cell (WBC) count and hsCRP; but positively with HDL-cholesterol (HDL-C) and hemoglobin. Multiple regression stepwise forward analysis revealed that BMI values, fasting blood glucose, WBC count, fasting hsCRP and hemoglobin were independent factors related to total testosterone. Furthermore, total testosterone is lower in elderly men with metabolic syndrome, according to National Cholesterol Education Program criteria with a modification of waist circumference. However, free testosterone plays a small role in association with metabolic factors in this elderly men's population.

CONCLUSION

Total testosterone level is significantly related to metabolic and inflammatory factors in elderly men. Low total testosterone may be a significant indicator for development of metabolic syndrome in elderly men.

The relationships between insulin resistance and components of metabolic syndrome in Taiwanese Asians

Metabolic syndrome (MetS) is a complicated clinicopathological entity with clustering of cardiovascular and metabolic risk factors, which includes central obesity, hypertension, dyslipidemia and glucose intolerance. There were many studies investigating a wide variety of clinical and pathophysiological aspects of this syndrome. However, the cutoffs of the components of MetS are not yet being evaluated by measured the insulin resistance (IR) directly. In this study, we enrolled 564 (male/female: 250/314) middle-aged healthy subjects. Each of the male and the female group was further divided into four subgroups (group 1 to group 4). Group 4 had the top 25 percentile of most severe IR determined by insulin suppression test. We then obtain the mean values of each component of the MetS in group 4 and compared them with the definitions of World Health Organization, National Cholesterol Education Program Adult Treatment Panel III, European Study Group of Insulin Resistance and International Diabetes Federation. The means of the blood pressure (BP) (male, 125/81; female, 125/80 mmHg) and the triglyceride (TG) (male, 1.6; female, 1.4 mmol/l) in group 4 were lower, and the fasting plasma glucose (6.2 mmol/l) was higher than the cutoffs of the other four sets of the criteria. The means of the high-density lipoprotein cholesterol (male, 0.9; female, 1.03 mmol/l) and the body mass index (male, 26.9; female 26.1 kg/m(2)) in group 4 were consistent with the cutoffs of other four groups and also the Taiwan Health Department criteria. In conclusion, we suggest to lower the cutoffs of the BP from 140/90 to 125/80 mmHg, TG from 1.7 to 1.6 mmol/l for males and 1.4 mmol/l for females for MetS definition, at least in Taiwan. This may help to early detect subjects under high risk of future coronary heart disease and diabetes. Still, these newly proposed cutoffs need larger-scale epidemiological studies to confirm.

Sibutramine improves insulin sensitivity without alteration of serum adiponectin in obese subjects with Type 2 diabetes

AIM

To evaluate the effect of sibutramine on weight loss, insulin sensitivity and serum adiponectin levels in obese patients with Type 2 diabetes.

METHODS

This study is a randomized, double-blind, placebo-controlled parallel comparison study of sibutramine 15 mg/day and placebo. Forty-eight eligible obese patients with Type 2 diabetes (age between 30 and 75 years with body mass index > or = 27 kg/m(2)) were randomly assigned to receive either placebo (n = 24) or sibutramine (15 mg/day) (n = 24) for 6 months. Fifteen subjects in each group underwent meal tests and modified insulin suppression tests before and after 6 months' treatment.

RESULTS

After 6 months of sibutramine treatment statistically significant changes from baseline were observed for body weight (85.4 +/- 2.5 vs. 82.9 +/- 2.4 kg, P < 0.005) and body mass index (32.0 +/- 0.7 vs. 31.4 +/- 0.6 kg/m(2), P < 0.05) without a significant alteration of waist-hip ratio (W/H), blood pressure, heart rate, glycaemic parameters or lipid profiles. The steady-state plasma glucose (SSPG) level during the modified insulin suppression test was significantly reduced in the sibutramine group (17.33 +/- 2.92 vs. 14.29 +/- 4.19 mmol/l, P < 0.05) despite similar steady-state plasma insulin (SSPI) concentrations. In addition, serum adiponectin and C-reactive protein (CRP) levels remained unchanged, although modest weight reduction was achieved after sibutramine treatment. There were also no significant correlations between changes in serum adiponectin and reduction of SSPG or body weight. Daily ambient plasma insulin and glucose concentrations in response to a test meal were not significantly different in subjects receiving sibutramine treatment.

CONCLUSIONS

We conclude that treatment with sibutramine 15 mg once daily effectively reduces weight and enhances insulin sensitivity without alteration of serum adiponectin levels in obese patients with Type 2 diabetes.

C-reactive protein and risk factors for peripheral vascular disease in subjects with Type 2 diabetes mellitus

AIMS

To compare the importance of different inflammatory markers and traditional risk factors in predicting peripheral vascular disease (PVD) in patients with Type 2 diabetes mellitus.

METHODS

A cross-sectional analysis of 30 Type 2 diabetic patients with PVD defined by ankle-brachial index (ABI) < 0.9, and 60 Type 2 diabetic patients without PVD (ABI > 1.0). Overnight blood was drawn and sent for study.

RESULTS

Longer diabetic duration (15 +/- 8 vs. 10 +/- 7 years, P = 0.007), higher serum creatinine level (0.11 +/- 0.04 vs. 0.09 +/- 0.03 mmol/l, P = 0.001), higher total cholesterol/high-density lipoprotein-cholesterol (TC/HDL-C) ratio (5.2 +/- 1.6 vs. 4.3 +/- 1.1, P = 0.004) and increased hypertension status (70% vs. 52%, P = 0.014) and cerebral infarction (CI) history (23% vs. 3%, P = 0.009) were noted in Type 2 diabetes with PVD. Those with PVD also showed significantly higher serum levels of C-reactive protein (CRP) (median 0.282 vs. 0.102 mg/dl, P < 0.001) and interleukin (IL)-6 (10.6 +/- 1.81 vs 1.6 +/- 4.6 pg/ml, P = 0.001). Multivariate regression analysis showed that higher serum levels of C-reactive protein (CRP), longer diabetic duration, and use of angiotensin converting enzyme inhibitor (ACEI) were independently associated with PVD in Type 2 diabetes mellitus.

CONCLUSIONS

Type 2 diabetic patients with PVD had longer diabetic duration, higher serum creatinine levels, higher TC/HDL-C ratio, higher hypertension and CI history and higher CRP and IL-6 levels. Only serum CRP level, diabetic duration, and use of ACEI were independently associated with PVD in Type 2 diabetes mellitus.

Sagittal abdominal diameter is associated with insulin sensitivity in Chinese hypertensive patients and their siblings

The purpose of the study is to observe the relation between anthropometric measurements, focusing on sagittal abdominal diameter (SAD), and insulin sensitivity indices in Chinese hypertensive patients and their siblings. In total, 907 participants, 537 hypertensive and 370 nonhypertensive, from 311 Taiwanese families were drawn from the Stanford Asia and Pacific Program for Hypertension and Insulin Resistance for the study. The participants received anthropometric measurements and 75-g oral glucose tolerance tests after an overnight fast. Fasting insulin, homeostasis model assessment for insulin resistance (HOMA-IR), and the insulin sensitivity index ISI(0,120) were chosen as surrogate measures of insulin sensitivity. In addition to Pearson and partial correlations, we used generalized estimating equations (GEEs) to examine the association between anthropometric measurements and insulin sensitivity indices. A small deviance in the GEEs indicates the goodness of model fit, irrespective of the independence among variables. The hypertensive patients were older in age, wider in waist circumference (WC), larger in body mass index (BMI) and SAD, and more insulin resistant than the nonhypertensive counterparts. The logarithmic transformation of fasting insulin, HOMA-IR, and ISI(0,120) significantly correlated with SAD, WC, and BMI before and after adjustments for age and sex. The deviances of SAD in the GEEs were similar to those of WC in all subjects, while BMI had smaller deviances than SAD and WC in the hypertensive patients. Our results suggest that the performance of SAD in predicting insulin sensitivity is comparable with WC in Chinese hypertensive patients and their siblings. BMI, however, seems to have better association with insulin sensitivity than SAD and WC in the patients with hypertension.