All-cause mortality and serum insulin-like growth factor I in primary care patients

OBJECTIVE

Previous population-based studies provided conflicting results regarding the association of total serum insulin-like growth factor I (IGF-I) and mortality. The aim of the present study was to assess the relation of IGF-I levels with all-cause mortality in a prospective study.

DESIGN

DETECT (Diabetes Cardiovascular Risk-Evaluation: Targets and Essential Data for Commitment of Treatment) is a large, multistage, and nationally representative study of primary care patients in Germany. The study population included 2463 men and 3603 women. Death rates were recorded by the respective primary care physician. Serum total IGF-I levels were determined by chemiluminescence immunoassays and categorized into three groups (low, moderate, and high) according to the sex- and age-specific 10th and 90th percentiles.

RESULTS

Adjusted analyses revealed that men with low [hazard ratio (HR) 1.70 (95% confidence interval [CI] 1.05-2.73), p=0.03] and high [HR 1.76 (95% CI 1.09-2.85), p=0.02] IGF-I levels had higher risk of all-cause mortality compared to men with moderate IGF-I levels. The specificity of low IGF-I and high IGF-I levels increased with lower and higher cut-offs, respectively. No such association became apparent in women.

CONCLUSIONS

The present study revealed a U-shaped relation between IGF-I and all-cause mortality in male primary care patients.

One year of liraglutide treatment offers sustained and more effective glycaemic control and weight reduction compared with sitagliptin, both in combination with metformin, in patients with type 2 diabetes: a randomised, parallel-group, open-label trial

AIM

The aim of this study was to compare the efficacy and safety of once-daily human glucagon-like peptide-1 analogue liraglutide with dipeptidyl peptidase-4 inhibitor sitagliptin, each added to metformin, over 52 weeks in individuals with type 2 diabetes.

METHODS

In an open-label, parallel-group trial, metformin-treated participants were randomised to liraglutide 1.2 mg/day (n=225), liraglutide 1.8 mg/day (n=221) or sitagliptin 100 mg/day (n=219) for 26 weeks (main phase). Participants continued the same treatment in a 26-week extension.

RESULTS

Liraglutide (1.2 or 1.8 mg) was superior to sitagliptin for reducing HbA(1c) from baseline (8.4-8.5%) to 52 weeks: -1.29% and -1.51% vs. -0.88% respectively. Estimated mean treatment differences between liraglutide and sitagliptin were as follows: -0.40% (95% confidence interval -0.59 to -0.22) for 1.2 mg and -0.63% (-0.81 to -0.44) for 1.8 mg (both p<0.0001). Weight loss was greater with liraglutide 1.2 mg (-2.78 kg) and 1.8 mg (-3.68 kg) than sitagliptin (-1.16 kg) (both p<0.0001). Diabetes Treatment Satisfaction Questionnaire scores increased significantly more with liraglutide 1.8 mg than with sitagliptin (p=0.03). Proportions of participants reporting adverse events were generally comparable; minor hypoglycaemia was 8.1%, 8.3% and 6.4% for liraglutide 1.2 mg, 1.8 mg and sitagliptin respectively. Gastrointestinal side effects, mainly nausea, initially occurred more frequently with liraglutide, but declined after several weeks.

CONCLUSION

  Liraglutide provides greater sustained glycaemic control and body weight reduction over 52 weeks. Treatment satisfaction was significantly greater with 1.8 mg liraglutide, similar to 26-week results. The safety profiles of liraglutide and sitagliptin are consistent with previous reports.

Secretion of glucagon-like peptide-1 (GLP-1) in type 2 diabetes: what is up, what is down?

The incretin hormones gastric inhibitory polypeptide and especially glucagon-like peptide (GLP) have an important physiological function in augmenting postprandial insulin secretion. Since GLP-1 may play a role in the pathophysiology and treatment of type 2 diabetes, assessment of meal-related GLP-1 secretory responses in type 2 diabetic patients vs healthy individuals is of great interest. A common view states that GLP-1 secretion in patients with type 2 diabetes is deficient and that this applies to a lesser degree in individuals with impaired glucose tolerance. Such a deficiency is the rationale for replacing endogenous incretins with GLP-1 receptor agonists or re-normalising active GLP-1 concentrations with dipeptidyl peptidase-4 inhibitors. This review summarises the literature on this topic, including a meta-analysis of published studies on GLP-1 secretion in individuals with and without diabetes after oral glucose and mixed meals. Our analysis does not support the contention of a generalised defect in nutrient-related GLP-1 secretory responses in type 2 diabetes patients. Rather, factors are identified that may determine individual incretin secretory responses and explain some of the variations in published findings of group differences in GLP-1 responses to nutrient intake.

Reference levels for serum thyroid function tests of diagnostic and prognostic significance

A controversy exists on the value of upper thyrotropin (TSH) reference level. Currently available studies are based on cross-sectional data leaving uncertainty about the prognostic significance of the upper TSH reference level. With the present study we sought to establish reference values for serum thyroid function tests that are of both diagnostic and prognostic significance. We used data from the prospective population-based Study of Health in Pomerania (SHIP) with a 5 year follow-up (6080 person-years). We included data from 1203 subjects (525 women) without prevalent subclinical or manifest thyroid disorders. An event-free reference population was separated comprising 1053 subjects (473 women). When comparing reference values as analyzed from either the whole reference population or the event-free reference population, we observed notable differences in TSH reference intervals. While the lower TSH reference values were similar in both populations, the upper value was 1.95 mIU/l and thus by 7.6% lower in subjects without incident events compared to the whole reference population. Both populations did not substantially differ with respect to serum FT3 and FT4 reference intervals. The upper TSH reference value is lower than recommended when both diagnostic and prognostic significance are considered in the definition of the TSH reference range.

Total and cardiovascular disease mortality predicted by metabolic syndrome is inferior relative to its components

OBJECTIVES

This study examined the predictive role of metabolic syndrome (MetS) and its single components for total and cardiovascular disease (CVD) mortality.

METHODS

We analyzed data from 3,927 participants aged 20-79 years without history of CVD, recruited for the prospective population-based Study of Health in Pomerania (SHIP). During the mean 7.2 years (25 (th), 6.6; 75 (th): 8.0) of follow-up, 240 deaths (79 CVD deaths) occurred. MetS was defined by National Cholesterol Education Program Adult Treatment Panel III guidelines. The association of MetS with total and CVD mortality was analyzed by Cox proportional hazards regression models. The impact of single MetS components on survival time was compared using standardized beta coefficients from multivariable linear regression models.

RESULTS

Baseline MetS prevalence was 28.8%. Age- and gender-adjusted Cox models revealed that participants with MetS had an increased risk of total mortality (hazard ratio (HR) 1.41; 95% confidence interval (95% CI) 1.09-1.82) and CVD mortality (HR 1.82; 95% CI 1.22-3.13) compared to participants without MetS. Of the single MetS components, participants with increased waist circumference (WC) and glucose levels exposed highest risk of total (HR 1.49; 95% CI 1.10-2.01; HR 2.13; 95% CI 1.58-2.90, respectively) and CVD mortality (HR 2.02; 95% CI 1.13-3.61; HR 3.15; 95% CI 1.94-5.11, respectively). Increasing WC or glucose by 1 standard deviation (SD) significantly decreased age- and gender-adjusted beta coefficients for survival time by 0.09, and 0.08 SD, respectively.

CONCLUSION

There was no added predictive value of MetS beyond its individual components with respect to mortality risk. Attention should be redirected to the individual components, particularly visceral obesity and high glucose, to treat each abnormality appropriately.