Current strategies for evaluating, monitoring, and treating type 2 diabetes mellitus

Hypertension, Diabetes Type II, and Their Association: Role of Arterial Stiffness

In patients with both hypertension and type II diabetes, the systolic blood pressure (SBP) increases linearly with age, while that of diastolic blood pressure (DBP) declines curvilinearly as early as age 45, all suggesting the development of increased arterial stiffness. Increased stiffness is an important, independent, and significant risk predictor in subjects with hypertension and diabetes. In patients with both diseases, stiffness assessed at the same mean arterial pressure (MAP) was significantly higher in diabetic patients. Arterial stiffness is related to age, heart rate (HR), and MAP, but in diabetic patients, it also related to diabetes duration and insulin treatment (IT). In the metabolic syndrome (MetSyn), diabetes also acts on the small arteries through capillary rarefaction to reduce the effective length of the arterial tree, increases the reflected pulse wave and thus the pulse pressure (PP). These studies indicate that diabetes and hypertension additively contribute to increased pulsatility and suggest that any means to reduce stiffness would be beneficial in these conditions.

A phase II, randomized, placebo-controlled, double-blind, multi-dose study of SRT2104, a SIRT1 activator, in subjects with type 2 diabetes

AIM

SRT2104 is a selective activator of SIRT1. In animal models, SRT2104 improves glucose homeostasis and increases insulin sensitivity. We evaluated the tolerability and pharmacokinetics of SRT2104, and its effects on glycaemic control, in adults with type 2 diabetes mellitus.

METHOD

Type 2 diabetics with glycosylated haemoglobin (HbA1c) ≥ 7.5% and ≤10.5%, fasting glucose ≥160 and ≤240 mg dl(-1) , and on stable doses of metformin were evenly randomized to placebo or SRT2104 0.25 g, 0.5 g, 1.0 g or 2.0 g, administered orally once daily for 28 days. Changes in fasting and post-prandial glucose and insulin were analyzed.

RESULTS

Safety evaluation found no major differences between groups in the frequency of adverse events. SRT2104 concentrations did not increase in a dose-proportional fashion. Significant variability in exposure was observed. Treatment with SRT2104 did not lead to any consistent, dose-related changes in glucose or insulin. Day 28 change from baseline (mean (SD)): fasting glucose (mmol l(-1) ) = -1.17 (2.42), -1.11 (3.45), -0.52 (2.60), -0.97 (2.83) and -0.15 (2.38) for placebo, 0.25 g, 0.5 g, 1.0 g and 2.0 g, respectively. Day 28 change from baseline (mean (SD)): fasting insulin (mmol l(-1) ) = 1.0 (51.66), 8.9 (95.04), -6.9 (41.45), 4.1 (57.16) and 15.2 (138.79) for placebo, 0.25 g, 0.5 g, 1.0 g and 2.0 g, respectively) Treatment with SRT2104 was associated with improvement in lipid profiles.

CONCLUSION

Treatment with SRT2104 for 28 days did not result in improved glucose or insulin control which is likely due to the observed pharmacokinetics which were not dose proportional and had large between subject variability.

Evaluation of pulmonary function changes in children with type 1 diabetes mellitus in Upper Egypt

BACKGROUND

Diabetes mellitus is a leading cause of morbidity and mortality among children across the world and is responsible for a growing proportion of global healthcare expenditure. However, limited data are available on lung dysfunction in children with diabetes.

AIM

The aim of this study was to evaluate the pulmonary function changes in children with type 1 diabetes mellitus (T1DM).

METHODS

We studied 60 children with T1DM (mean age 10.5 ± 2.32 years; disease duration 2.45 ± 0.6 years, and 50 healthy control children (mean age 9.9 ± 2.5 years). Spirometry was performed for all individuals to measure forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), FEV1/FVC ratio, and peak expiratory flow rate (PEFR). Glycemic control was assessed on the basis of glycated hemoglobin (HbA1c), with HbA1c values <8% considered to indicate good glycemic control, and HbA1c values ⩾8% to indicate poor control.

RESULTS

There was significant reduction in all spirometeric parameters in diabetic children in comparison with healthy control children. Children with poor glycemic control had significant impairment in lung functions compared with those with good glycemic control.

CONCLUSIONS

T1DM in children leads to impairment of lung functions and this impairment increases with poor glycemic control.

Early hepatic insulin resistance in mice: a metabolomics analysis

When fed with a high-fat safflower oil diet for 3 wk, wild-type mice develop hepatic insulin resistance, whereas mice lacking glycerol-3-phosphate acyltransferase-1 retain insulin sensitivity. We examined early changes in the development of insulin resistance via liver and plasma metabolome analyses that compared wild-type and glycerol-3-phosphate acyltransferase-deficient mice fed with either a low-fat or the safflower oil diet for 3 wk. We reasoned that diet-induced changes in metabolites that occurred only in the wild-type mice would reflect those metabolites that were specifically related to hepatic insulin resistance. Of the identifiable metabolites (from 322 metabolites) in liver, wild-type mice fed with the high-fat diet had increases in urea cycle intermediates, consistent with increased deamination of amino acids used for gluconeogenesis. Also increased were stearoylglycerol, gluconate, glucarate, 2-deoxyuridine, and pantothenate. Decreases were observed in S-adenosylhomocysteine, lactate, the bile acid taurocholate, and 1,5-anhydroglucitol, a previously identified marker of short-term glycemic control. Of the identifiable metabolites (from 258 metabolites) in plasma, wild-type mice fed with the high-fat diet had increases in plasma stearate and two pyrimidine-related metabolites, whereas decreases were found in plasma bradykinin, alpha-ketoglutarate, taurocholate, and the tryptophan metabolite, kynurenine. This study identified metabolites previously not known to be associated with insulin resistance and points to the utility of metabolomics analysis in identifying unrecognized biochemical pathways that may be important in understanding the pathophysiology of diabetes.

Effect of periodontal treatment on glycemic control of diabetic patients: a systematic review and meta-analysis

OBJECTIVE

There is growing evidence that periodontitis may affect general health. This study was assigned to explore the robustness of observations that periodontal therapy leads to the improvement of glycemic control in diabetic patients.

RESEARCH DESIGN AND METHODS

A literature search (until March 2009) was carried out using two databases (MEDLINE and the Cochrane Library) with language restriction to English. Selection of publications was based on 1) original investigations, 2) controlled periodontal intervention studies where the diabetic control group received no periodontal treatment, and 3) study duration of > or =3 months.

RESULTS

Screening of the initial 639 identified studies and reference checking resulted in five suitable articles. A total of 371 patients were included in this analysis with periodontitis as predictor and the actual absolute change in A1C (DeltaA1C) as the outcome. The duration of follow-up was 3-9 months. All studies described a research population of type 2 diabetic patients in whom glycemic control improved after periodontal therapy compared with the control group (range DeltaA1C: Delta-1.17 up to Delta-0.05%). The studies in a meta-analysis demonstrated a weighted mean difference of DeltaA1C before and after therapy of -0.40% (95% CI -0.77 to -0.04%, P = 0.03) favoring periodontal intervention in type 2 diabetic patients. Nevertheless, this improvement in %A1C must be interpreted with care due to limited robustness as evidenced by heterogeneity among studies (59.5%, P = 0.04).

CONCLUSIONS

The present meta-analysis suggests that periodontal treatment leads to an improvement of glycemic control in type 2 diabetic patients for at least 3 months.

Segmentation of the Pathophysiological Stages of Diabetic Changes in the db/db Mouse

The db/db mouse is one of the diabetes mellitus animal models and if the pathophysiological stages of diabetic changes in the mouse model could simulate the stages in human diabetes, the db/db mouse could be used to better evaluate drug candidates. Blood insulin, HbA1c levels and morphological features of pancreatic islets in db/db mice were evaluated to determine the pathophysiological stage. At 6 weeks of age, db/db mice showed the highest level of plasma insulin and lowest level of HbA1c, and histopathological examination revealed enlarged islets with a circular shape and hypertrophic islet cells. By 9 and 12 weeks of age, the plasma insulin levels had decreased to mid levels and HbA1c had increased to mid to high levels; histopathological examination at this time revealed two types of islets coexisting, enlarged circular islets and small irregular-shaped islets. By 15 and 22 weeks of age, plasma insulin had decreased further to low levels and HbA1c was at its highest level; the histopathological examination at this time revealed an increase in irregular-shaped and small islets. Based on blood insulin levels, HbA1c levels and histopathology findings in the db/db mice in this study, the clinical staging of diabetic changes were recognized. The pathophysiological stages of diabetes mellitus in this animal model were similar to the stages in humans.

Pharmacokinetic and pharmacodynamic advantages of insulin analogues and premixed insulin analogues over human insulins: impact on efficacy and safety

Human insulin preparations administered to patients with diabetes mellitus fail to reproduce the normal physiologic pattern of insulin secretion. Modifications have been made in the amino acid sequence of the insulin molecule with the aim of overcoming the pharmacokinetic shortcomings of human insulins. Such modifications have produced long-acting analogues, with relatively flat time-action profiles, for controlling glycemic levels between meals; and rapid-acting analogues with a fast onset and short duration of action, for controlling postprandial hyperglycemia. Premixed formulations of the rapid-acting analogues, containing both rapid-acting soluble and intermediate-acting protaminated forms, are also available. Trials of long-acting insulin analogues have consistently shown efficacy in controlling fasting plasma glucose and glycosylated hemoglobin (HbA1c), as well as a markedly reduced risk of hypoglycemia compared with neutral protamine Hagedorn insulin. The rapid-acting and premixed analogues offer better control of postprandial glucose excursions than do regular human insulin, resulting in similar or lower HbA1c levels. Furthermore, the analogues can offer patients greater flexibility and more convenience in administration compared with human insulins. This review provides an overview of the insulin analogues available today and describes their structure, pharmacokinetics, pharmacodynamics, efficacy, and safety.