Factors associated with progression to pre-diabetes: a recurrent events analysis

Association of Periodontal Condition With Impaired Glucose Tolerance: Results of a 15-Year Follow-Up Study

OBJECTIVES

The aim of this study was to investigate whether periodontal condition is associated with the development of impaired glucose tolerance (IGT).

MATERIAL AND METHODS

This study was based on a subpopulation of a cohort of persons born in 1935 and living in Oulu, Finland, on October 1, 1990. The participants were normoglycemic (no previously diagnosed diabetes mellitus and a 2-h oral glucose tolerance test [OGTT] blood glucose < 7.8 mmol/L) in the baseline examinations (1990-1992) and had fasting blood glucose < 7.0 mmol/L in the follow-up examinations (2007-2008) (n = 225). The outcome was IGT on follow-up, measured by a blood glucose level of ≥ 7.8 mmol/L after OGTT. The exposure was the periodontal condition at baseline categorized into four groups: 0, 1-6, ≥ 7 sites with deepened (≥ 4 mm) periodontal pockets, and edentulousness.

RESULTS

A total of 23% of the participants developed IGT. The adjusted incidence rate ratios with 95% confidence intervals (CI) for dentate participants with 1-6 sites and ≥ 7 sites with deepened periodontal pockets, and edentate participants (reference category dentate participants without deepened periodontal pockets) were 1.5 (95% CI, 0.6-4.0), 1.8 (95% CI, 0.7-4.4), and 1.6 (95% CI, 0.6-4.0), respectively.

CONCLUSIONS

Poor periodontal condition may predispose individuals to IGT; however, further studies on this matter are warranted.

Protein Intake and Human Health: Implications of Units of Protein Intake

Understanding the health effects of protein intake is bedeviled by a number of factors, including protein quality and source. In addition, different units, including grams, grams per kilogram body weight (g/kg BW), and percent energy, may contribute to confusion about protein's effects on health, especially BW-based units in increasingly obese populations. We aimed to review the literature and to conduct a modeling demonstration of various units of protein intake in relation to markers of cardiometabolic health. Data from the Framingham Heart Study Offspring (n = 1847; 60.3 y; 62.5% women) and Third Generation (n = 2548; 46.2 y; 55.3% women) cohorts and the NHANES 2003-04 (n = 1625; 46.2 y; 49.7% women) and 2005-06 (n = 1347; 43.7 y; 49.5% women) cycles were used to model cross-sectional associations between 7 protein units (grams, percent energy, g/kg ideal BW, g/kg actual BW, BW-adjusted g/kg actual BW, g/kg lean BW, and g/kg fat-free BW) and 9 cardiometabolic outcomes (fasting glucose, systolic and diastolic blood pressure, total and HDL cholesterol, triglycerides, BMI, waist circumference, and estimated glomerular filtration rate). The literature review indicated the use of myriad units of protein intake, with differential results on cardiometabolic outcomes. The modeling demonstration showed units expressed in BW were confounded by BW, irrespective of outcome. Units expressed in grams, percent energy, and ideal BW showed similar results, with or without adjustment for body size. After adjusting for BW, results of units expressed in BW aligned with results of grams, percent energy, and ideal BW. In conclusion, protein intake in cardiometabolic health appears to depend on protein's unit of expression. Authors should be specific about the use of WHO (g/kg ideal BW) compared with US (g/kg actual BW) units, and ideally use gram or percent energy in observational studies. In populations where overweight/obesity are prevalent, intake based on actual BW should be reevaluated.

Caloric restriction recovers impaired β-cell-β-cell gap junction coupling, calcium oscillation coordination, and insulin secretion in prediabetic mice

Caloric restriction can decrease the incidence of metabolic diseases, such as obesity and Type 2 diabetes mellitus. The mechanisms underlying the benefits of caloric restriction involved in insulin secretion and glucose homeostasis are not fully understood. Intercellular communication within the islets of Langerhans, mediated by Connexin36 (Cx36) gap junctions, regulates insulin secretion dynamics and glucose homeostasis. The goal of this study was to determine whether caloric restriction can protect against decreases in Cx36 gap junction coupling and altered islet function induced in models of obesity and prediabetes. C57BL6 mice were fed with a high-fat diet (HFD), showing indications of prediabetes after 2 mo, including weight gain, insulin resistance, and elevated fasting glucose and insulin levels. Subsequently, mice were submitted to 1 mo of 40% caloric restriction (2 g/day of HFD). Mice under 40% caloric restriction showed reversal in weight gain and recovered insulin sensitivity, fasting glucose, and insulin levels. In islets of mice fed the HFD, caloric restriction protected against obesity-induced decreases in gap junction coupling and preserved glucose-stimulated calcium signaling, including Ca2+ oscillation coordination and oscillation amplitude. Caloric restriction also promoted a slight increase in glucose metabolism, as measured by increased NAD(P)H autofluorescence, as well as recovering glucose-stimulated insulin secretion. We conclude that declines in Cx36 gap junction coupling that occur in obesity can be completely recovered by caloric restriction and obesity reversal, improving Ca2+ dynamics and insulin secretion regulation. This suggests a critical role for caloric restriction in the context of obesity to prevent islet dysfunction.

Investigation of Prognostic Factors of Survival in Breast Cancer Using a Frailty Model: A Multicenter Study

Background

Using data from different health centers can provide more accurate knowledge of the survival prognostic factors and their effect on the patient's survival. In this multicenter study, we aimed to investigate the role of prognostic factors on breast cancer survival with large data set.

Methods

This historical cohort study was carried out using data from 1785 participants with breast cancer. Data were gathered from medical records of patients referring to 4 breast cancer research centers in Tehran, Iran, between 1997 and 2013. Age at diagnosis (year), size of the tumor, involve lymph nodes, tumor grade, type of surgery, auxiliary treatment of chemotherapy, radiotherapy, recurrence, and metastasis were the prognosis factors considered in this study. A shared frailty model with a gamma distribution for frailty term was used.

Results

The median follow-up period was 29.71 months with the interquartile range of 19 to 61 months. During the follow-up period, 337 (18.9%) patients died from breast cancer and 1448 (81.1%) survived. The 1-, 3-, 5-, and 10-year survival rates were 96%, 84%, 76%, and 58%, respectively. In the Cox model by centers, in Center A, the type of surgery, number of nodes involved, and the grade 3 tumor; in center B, age, radiotherapy, metastasis, and between 1 and 3 involved nodes; in center C, age, radiotherapy, recurrence, metastasis, tumor size, and grade 3 tumor; and in center D, chemotherapy, metastasis, and lymph nodes involved were significant. Shared frailty model showed that type of surgery, number of lymph nodes involved, metastasis, radiotherapy, and the tumor grade are the prognostic factors survival in breast cancer. The frailty variance was significant, and it affirmed there was significant variability between centers.

Conclusions

This study showed it is necessary to consider the frailty term in modeling multicenter survival studies and confirmed the importance of early diagnosis of cancer before the involvement of lymph nodes and the onset of metastasis and timely treatment could lead to longer life and increased quality of life for patients.