HbA(1c) as a screening tool for detection of Type 2 diabetes: a systematic review

A New Zealand linkage study examining the associations between A1C concentration and mortality

OBJECTIVE

To examine associations between A1C concentration and mortality in a New Zealand population.

RESEARCH DESIGN AND METHODS

During a Hepatitis Foundation screening campaign for hepatitis B (1999-2001), participants were offered A1C testing. The participants were anonymously linked to the national mortality collection to 31 December 2004. Hazard ratios (HRs) and 95% CIs adjusted for age, ethnicity, smoking, and sex were estimated using Cox regression.

RESULTS

There were 47,904 participants (71% Mâori, 12% Pacific, 5% Asian, and 12% other). A1C measurements were categorized as <4.0% (n = 142), 4.0 to <5.0% (reference category; n = 12,867), 5.0 to <6.0% (n = 30,222), 6.0 to <7.0% (n = 2,669), and >or=7.0% (n = 1,596); there were also 408 participants with a previous diabetes diagnosis. During the follow-up period, 815 individuals died. In those without a prior diabetes diagnosis, there were steadily increasing HRs from the A1C reference category to the highest category (>or=7.0%; HR 2.36 [95% CI 1.72-3.25]). As well as all-cause mortality, A1C was associated with mortality from diseases of the circulatory system; endocrine, nutritional, metabolic, and immunity disorders; and other and unknown causes. Mortality was also elevated in those with a prior diabetes diagnosis (5.19 [3.67-7.35]), but this was only partially explained by their elevated A1C levels.

CONCLUSIONS

This is the largest study to date of A1C levels and subsequent mortality risk. It confirms previous findings that A1C levels are strongly associated with subsequent mortality in both men and women without a prior diabetes diagnosis.

Comparison of periodontal and socioeconomic status between subjects with type 2 diabetes mellitus and non-diabetic controls

BACKGROUND

The association among periodontal conditions, socioeconomic status (SES), and diabetes has been reported. However, there is a lack of published data comparing periodontal conditions among individuals with poorly controlled type 2 diabetes mellitus (T2D). The aim of the present study was to compare the periodontal conditions and SES between subjects with T2D and non-diabetic controls.

METHODS

A total of 75 (31 males and 44 females) individuals with T2D (62 poorly controlled and 13 well-controlled) and 99 non-diabetic patients (healthy controls; 51 males and 48 females) participated in the study. Plaque index (PI), bleeding on probing (BOP), and probing depth (PD) were investigated. Random blood glucose level was recorded. Premolar and molar marginal bone loss (MBL) was measured digitally on scanned orthopantomograms.

RESULTS

Individuals with poorly controlled T2D had increased MBL in molars and maxillary premolars (P<0.05) compared to individuals with well-controlled T2D. PI, BOP, and PD of 4 to <6 mm were increased in individuals with poorly controlled T2D compared to those with well-controlled T2D (P<0.001). There was no difference between the diabetic groups when PD was >or=6 mm. Individuals with poorly controlled T2D had a lower SES compared to patients with well-controlled T2D (P<0.05). Illiteracy and the number of missing teeth were not different between the groups.

CONCLUSIONS

Radiologic and clinical indicators of periodontal destruction were increased in individuals with poorly controlled T2D. Low SES aggravated the periodontal condition in individuals with T2D.

Insulin, glucose and glycated hemoglobin in Alzheimer’s and vascular dementia with and without superimposed Type II diabetes mellitus condition

Increased concentrations of insulin, glucose and glycohemoglobin are associated with Type II diabetes mellitus (DM) and recognized as characteristic markers of the disease; in Alzheimer's (AD), Vascular dementia (VaD), and both dementia's with superimposed diabetes (AD + DM, VaD + DM) the knowledge is scarce. The sample (n = 122; males = 60; mean age = 73 +/- 7) comprised DM, AD, VaD, AD + DM, and VaD + DM patients, and healthy controls (C). The ANOVA's yielded significant differences between groups: Insulin p = 3.7 x 10(-3); Glucose p < 10(-12); Glycohemoglobin p = 9.2x10(-4). Comparisons between groups (DM vs. C, AD + DM vs. AD, VaD + DM vs. VaD, and demented DM vs. non-demented DM) resulted significant for all variables (Bonferroni's statistic, alpha = 0.05). Diabetic and diabetic demented patients presented significant increases largely different from controls (0.01 < p < 0.001), unlike the non-significant changes in their non-diabetic counterparts; linear relationships were found across all groups. The correlation's insulin/glucose and insulin/glycohemoglobin change to positive within demented groups, indicating a different performance of insulin in demented and non-demented subjects.

TRAF4 functions as an intermediate of GITR-induced NF-kappaB activation

Members of the tumor necrosis factor receptor (TNFR) family regulate the activation, differentiation, and function of many cell types, including cells of the immune system. TNFR-associated factors (TRAFs) function as adapter molecules controlling signaling pathways triggered by TNFR family members, such as activation of nuclear factor kappaB (NF-kappaB). Despite intensive research, the function of TRAF4 in signaling pathways triggered by TNFR-related proteins remains enigmatic. Intriguingly, our functional studies indicated that TRAF4 augments NF-kappaB activation triggered by glucocorticoid-induced TNFR (GITR), a receptor expressed on T cells, B cells, and macrophages. Further analyses revealed that TRAF4-mediated NF-kappaB activation downstream of GITR depends on a previously mapped TRAF-binding site in the cytoplasmic domain of the receptor and is inhibited by the cytoplasmic protein A20. GITR is thought to inhibit the suppressive function of regulatory T cells (Treg cells) and to promote activation of T cells. Taken together, our studies provide the first indications that TRAF4 elaborates GITR signaling and suggest that TRAF4 can modulate the suppressive functions of Treg cells.