Performance of a multi-marker diabetes risk score in the Insulin Resistance Atherosclerosis Study (IRAS), a multi-ethnic US cohort

Plasma adiponectin levels and type 2 diabetes risk: a nested case-control study in a Chinese population and an updated meta-analysis

Results from previous prospective studies assessing the relation between adiponectin and type 2 diabetes (T2D) were not entirely consistent, and evidence in Chinese population is scarce. Moreover, the last meta-analysis did not examine the impact of metabolic variables on the adiponectin-T2D association. Therefore, we prospectively evaluated the adiponectin-T2D association among 571 T2D cases and 571 age-sex-matched controls nested within the Singapore Chinese Health Study (SCHS). Furthermore, we conducted an updated meta-analysis by searching prospective studies on Pubmed till September 2016. In the SCHS, the odds ratio of T2D, comparing the highest versus lowest tertile of adiponectin levels, was 0.30 (95% confidence interval: 0.17, 0.55) in the fully-adjusted model. The relation was stronger among heavier participants (body mass index ≥23 kg/m²) compared to their leaner counterparts (P for interaction = 0.041). In a meta-analysis of 34 prospective studies, the pooled relative risk was 0.53 (95% confidence interval: 0.47, 0.61) comparing the extreme tertiles of adiponectin with moderate heterogeneity (I² = 48.7%, P = 0.001). The adiponectin-T2D association remained unchanged after adjusting for inflammation and dyslipidemia markers, but substantially attenuated with adjustment for insulin sensitivity and/or glycaemia markers. Overall evidence indicates that higher adiponectin levels are associated with decreased T2D risk in Chinese and other populations.

Individual serum saturated fatty acids and markers of chronic subclinical inflammation: the Insulin Resistance Atherosclerosis Study

Recent evidence has documented distinct effects of individual saturated FAs (SFAs) on cardiometabolic outcomes, with potential protective effects from odd- and very long-chain SFAs (VLSFAs). Cross-sectional and prospective associations of individual serum SFAs (12:0, 14:0, 15:0, 16:0, 18:0, 20:0, 22:0, and total SFA) with proinflammatory biomarkers and adiponectin were investigated in 555 adults from the IRAS. Principal component analysis (PCA) of proinflammatory markers yielded three clusters: principal component (PC) 1: fibrinogen, white cell count, C-reactive protein; PC 2: plasminogen activator inhibitor-1 (PAI-1), TNF-α, IL-18; PC 3: IL-6 and IL-8. Cross-sectional analyses on proinflammatory PCs and adiponectin, and prospective analyses on 5 year PAI-1 and fibrinogen concentrations were conducted with multiple regression. Total SFA and 16:0 were positively associated with PC 1 and PC 2, and negatively associated with adiponectin. The 14:0 was positively associated with PC 1 and negatively associated with adiponectin. In contrast, 15:0, 20:0, and 22:0 were negatively associated with PC 2, and 20:0 and 22:0 were positively associated with adiponectin. The 18:0 was negatively associated with PC 3. Prospectively, 15:0, 18:0, 20:0, and 22:0 were negatively associated with 5 year PAI-1 concentrations. The results demonstrate that individual SFAs have distinct roles in subclinical inflammation, highlighting the unique metabolic impacts of individual SFAs.

An exploratory retrospective assessment of a quantitative measure of diabetes risk: medical management and patient impact in a primary care setting

BACKGROUND

Primary care providers with limited time and resources bear a heavy responsibility for chronic disease prevention or progression. Reliable clinical tools are needed to risk stratify patients for more targeted care. This exploratory study examined the care of patients who had been risk stratified regarding their likelihood of clinically progressing to type 2 diabetes.

METHODS

This was a retrospective chart review pilot study conducted to assess a primary care provider's use of a risk screening test. In this quality improvement project, the result of the risk screening was examined in relation to its influence on medical management and clinical impact on patients at risk for diabetes. All providers were board certified in family medicine and had more than 10 years clinical experience in managing diabetes and prediabetes. No specific clinical practice guidelines were mandated for patient care in this pilot study. Physicians in the practice group received an orientation to the diabetes risk measure and its availability for use in a pilot study to be conducted over a 6-month period. We identified the 696 nondiabetic adults in family practices who received a risk screening test (PreDx(®), a multi-marker blood test that estimates the 5-year likelihood of conversion to type 2 diabetes) between June and November 2011 for a 6-month sample. A comparison group of 2,002 patients from a total database of 3.2 million patients who did not receive the risk test was randomly selected from the same clinical database after matching for age, sex, selected diagnoses, and metabolic risk factors. Patient groups were compared for intensity of care provided and clinical impact.

RESULTS

Compared to patients with a similar demographic and diagnostic profile, patients who had the risk test received more intensive primary care and had better clinical outcome than comparison patients. Risk-tested patients were more likely to return for follow-up visits, be monitored for relevant cardio-metabolic risk factors, and receive prescription medications with P<0.001. Further, intensity of care was associated with the level of risk test result: patients with moderate or high scores were more likely to return for follow-up visits and receive prescription medications than patients with low scores. All P-values for comparison patients between the low and moderate groups, low and high groups, and moderate and high groups resulted in P<0.001. Risk-tested patients were more likely than their comparison group counterparts to achieve weight reduction, lowered blood pressure, and improved blood glucose and cholesterol as demonstrated by P-values of <0.001.

CONCLUSION

Use of a risk stratification test in primary care may help providers to more effectively identify high risk patients, manage diabetes risk, increase patient involvement in diabetes risk management, and improve clinical outcomes. A randomized controlled study is the next step to investigate the impact of diabetes risk stratification in primary care.

Clinical use of adiponectin as a marker of metabolic dysregulation

Adiponectin concentrations exhibit strong cross-sectional relationships with obesity, inflammation, and diabetes. Adiponectin concentrations have been extensively evaluated as epidemiologic markers of diabetes and cardiovascular disease risk. In the present review we will provide an overview of these epidemiologic relationships as the backdrop for an evaluation of the clinical applications of adiponectin measurements. These include using adiponectin as an indicator of need for preventive or therapeutic intervention, as a predictor of response to therapy, and as a marker of therapeutic effectiveness. These efforts are laying the groundwork for the transition of adiponectin measurements from the laboratory to the clinic.

Bone Remodeling and Energy Metabolism: New Perspectives

Bone mineral, adipose tissue and energy metabolism are interconnected by a complex and multilevel series of networks. Calcium and phosphorus are utilized for insulin secretion and synthesis of high energy compounds. Adipose tissue store lipids and cholecalciferol, which, in turn, can influence calcium balance and energy expenditure. Hormones long-thought to solely modulate energy and mineral homeostasis may influence adipocytic function. Osteoblasts are a target of insulin action in bone. Moreover, endocrine mediators, such as osteocalcin, are synthesized in the skeleton but regulate carbohydrate disposal and insulin secretion. Finally, osteoblasts and adipocytes originate from the same mesenchymal progenitor. The mutual crosstalk between osteoblasts and adipocytes within the bone marrow microenvironment plays a crucial role in bone remodeling. In the present review we provide an overview of the reciprocal control between bone and energy metabolism and its clinical implications.

Body iron stores and heme-iron intake in relation to risk of type 2 diabetes: a systematic review and meta-analysis

BACKGROUND AND OBJECTIVE

Emerging evidence from biological and epidemiological studies has suggested that body iron stores and heme-iron intake may be related to the risk of type 2 diabetes (T2D). We aimed to examine the association of body iron stores and heme-iron intake with T2D risk by conducting a systematic review and meta-analysis of previously published studies.

RESEARCH DESIGN AND METHODS

Systematic review and subsequent meta-analysis were conducted by searching MEDLINE database up to June 22, 2012 to identify studies that analyzed the association of body iron stores or dietary heme-iron intake with T2D risk. The meta-analysis was performed using the effect estimates and 95% confidence intervals (CIs) to calculate the pooled risk estimates, while the heterogeneity among studies was examined using the I(2) and Q statistic.

RESULTS

The meta-analysis included 16 high-quality studies: 12 studies analyzed ferritin levels (4,366 T2D patients and 41,091 controls) and 4 measured heme-iron intake (9,246 T2D patients and 179,689 controls). The combined relative risk (RR) comparing the highest and lowest category of ferritin levels was 1.66 (95% CI: 1.15-2.39) for prospective studies, 2.29 (95% CI: 1.48-3.54) for cross-sectional studies with heterogeneity (Q = 14.84, p = 0.01, I(2) = 66.3%; Q = 44.16, p<0.001, I(2) = 88.7%). The combined RR comparing the highest and lowest category of heme-iron intake was 1.31 (95% CI: 1.21-1.43) with heterogeneity (Q = 1.39, p = 0.71, I(2) = 0%). No publication bias was found. Additional 15 studies that were of good quality, had significant results, and analyzed the association between body iron stores and T2D risk were qualitatively included in the systematic review.

CONCLUSIONS

The meta-analysis and systematic review suggest that increased ferritin levels and heme-iron intake are both associated with higher risk of T2D.