New measure of insulin sensitivity predicts cardiovascular disease better than HOMA estimated insulin resistance

Prediction of subclinical atherosclerosis in low Framingham risk score individuals by using the metabolic syndrome criteria and insulin sensitivity index

Background

Subclinical atherosclerosis can be present in individuals with an optimal cardiovascular risk factor profile. Traditional risk scores such as the Framingham risk score do not adequately capture risk stratification in low-risk individuals. The aim of this study was to determine if markers of metabolic syndrome and insulin resistance can better stratify low-risk individuals.

Methods

A cross-sectional study of 101 healthy participants with a low Framingham risk score and no prior morbidities was performed to assess prevalence of subclinical atherosclerosis using computed tomography (CT) and ultrasound. Participants were compared between groups based on Metabolic Syndrome (MetS) and Insulin-Sensitivity Index (ISI-cal) scores.

Results

Twenty three individuals (23%) had subclinical atherosclerosis with elevated CT Agatston score ≥1. Presence of both insulin resistance (ISI-cal <9.23) and fulfillment of at least one metabolic syndrome criterion denoted high risk, resulting in significantly improved AUC (0.706 95%CI 0.588–0.822) over the Framingham risk score in predicting elevated CT Agatston score ≥1, with net reclassification index of 50.9 ± 23.7%. High-risk patients by the new classification also exhibited significantly increased carotid intima thickness.

Conclusions

The overlap of insulin resistance and presence of ≥1 criterion for metabolic syndrome may play an instrumental role in identifying traditionally low-risk individuals predisposed to future risk of atherosclerosis and its sequelae.

Nodular glomerulosclerosis in a kidney transplant recipient with impaired glucose tolerance: diabetic or idiopathic? A case report and literature review

Nodular glomerulosclerosis, typically diagnosed in patients with diabetes mellitus, has been reported in native kidneys of pre-diabetic patients but similar cases in kidney transplant recipients are lacking. We describe a case of nodular glomerulosclerosis in a kidney transplant recipient who had not been found to be diabetic despite regular screening and discuss the implications for the pathogenesis and diagnosis of nodular glomerulosclerosis and screening of post-transplant diabetes mellitus.

The ZJU index: a useful indicator for recognizing insulin resistance in the Chinese general population

AIMS

Nonalcoholic fatty liver disease (NAFLD) is a hepatic manifestation of metabolic syndrome and is closely associated with insulin resistance (IR). The ZJU index is based on body mass index (BMI), fasting plasma glucose (FPG), triglycerides (TG) and the serum alanine aminotransferase-to-aspartate transaminase ratio, and is proven to be a novel and effective parameter for screening NAFLD in the Chinese population. We aimed to analyze the relationship between the ZJU index and IR.

METHODS

A cross-sectional study of 3329 Chinese adults was performed. Blood pressure (BP), anthropometric measurements and biochemical parameters were tested. The BMI, ZJU index and homeostasis model assessment of IR (HOMA-IR) were calculated.

RESULTS

In both genders, BP, waist circumference, BMI, total cholesterol, TG, low-density lipoprotein cholesterol levels, FPG, postprandial glucose levels, fasting insulin and the HOMA-IR gradually increased, while the HDL-C decreased across the quartiles of the ZJU index (P < 0.001). The logistic regression analysis showed that the risk of IR was significantly elevated in the highest quartile of the ZJU index. Additionally, the area under the receiver operating characteristic curve of the ZJU index was 0.833 (95 % CI 0.809-0.858) in males and 0.788 (95 % CI 0.758-0.818) in females and was relatively higher than other common variables.

CONCLUSIONS

The ZJU index is a useful indicator for recognizing IR in the Chinese general population.

Lithium or Valproate Adjunctive Therapy to Second-generation Antipsychotics and Metabolic Variables in Patients With Schizophrenia or Schizoaffective Disorder

OBJECTIVE

People with schizophrenia are at greater risk for cardiovascular disease and their overall mortality rate is elevated compared to the general population. The metabolic side effects of antipsychotic medications have been widely studied; however, the effect of adding conventional mood stabilizers, such as lithium and valproate, to antipsychotic medication has not been assessed in terms of metabolic risk. The primary purpose of this secondary analysis was to examine whether treatment with lithium or valproate in addition to a second-generation antipsychotic is associated with poorer metabolic outcomes than treatment with a second-generation antipsychotic without lithium or depakote.

METHODS

Baseline data from 3 studies, which included measurement of body mass index, waist circumference, fasting glucose, insulin, homeostatic model assessment of insulin resistance, insulin sensitivity index, glucose utilization, and acute insulin response to glucose, were included in the analysis.

RESULTS

No differences were found between those taking lithium or valproate and those who were not in terms of fasting glucose, fasting insulin, and homeostatic model assessment of insulin resistance. Insulin sensitivity was lower among participants taking lithium or valproate. Participants taking lithium or valproate had a higher body mass index than those not taking conventional mood stabilizers, although the difference did not reach statistical significance.

CONCLUSIONS

These cross-sectional findings suggest it may be beneficial to monitor insulin sensitivity and body mass index in patients taking lithium or valproate in combination with a second-generation antipsychotic.

Metabolic responses to a traditional Mexican diet compared with a commonly consumed US diet in women of Mexican descent: a randomized crossover feeding trial

BACKGROUND

Mexican immigrants are disproportionally affected by diet-related risk of metabolic dysfunction. Whether adhering to a traditional Mexican diet or adopting a US diet contributes to metabolic changes associated with future risk of type 2 diabetes and other chronic diseases has not been investigated.

OBJECTIVE

The purpose of this study was to test in a randomized crossover feeding trial the metabolic responses to a Mexican diet compared with a commonly consumed US diet.

DESIGN

First- and second-generation healthy women of Mexican descent (n = 53) were randomly assigned in a crossover design to consume a Mexican or US diet for 24 d each, separated by a 28-d washout period. Diets were eucaloric and similar in macronutrient composition. The metabolic responses to diets were assessed by measuring fasting serum concentrations of glucose, insulin, insulin-like growth factor 1 (IGF-1), insulin-like growth factor binding protein 3 (IGFBP-3), adiponectin, C-reactive protein (CRP), and interleukin 6 (IL-6), as well as the homeostasis model assessment of insulin resistance (HOMA-IR) at the beginning and end of each period. Linear mixed models tested the intervention effect on the biomarkers, while adjusting for diet sequence, feeding period, baseline and washout biomarker concentrations, age, acculturation, and BMI.

RESULTS

Compared with the US diet, the Mexican diet reduced insulin by 14% [geometric means (95% CIs): 9.3 (8.3, 10.3) compared with 8.0 (7.2, 8.9) μU/mL; P = 0.02], HOMA-IR by 15% [2.0 (1.8, 2.3) compared with 1.7 (1.6, 2.0); P = 0.02], and IGFBP-3 by 6% (mean ± SEM: 2420 ± 29 compared with 2299 ± 29 ng/mL; P < 0.01) and tended to reduce circulating concentrations of IGF-1 by 4% (149 ± 2.6 compared with 144 ± 2.5 ng/mL; P = 0.06). There was no significant intervention effect on serum concentrations of glucose, adiponectin, CRP, or IL-6 in the US compared with the Mexican diet.

CONCLUSION

Compared with the commonly consumed US diet, the traditional Mexican diet modestly improved insulin sensitivity under conditions of weight stability in healthy women of Mexican descent, while having no impact on biomarkers of inflammation. This trial was registered at clinicaltrials.gov as NCT01369173.

The Evidence for Saturated Fat and for Sugar Related to Coronary Heart Disease

Dietary guidelines continue to recommend restricting intake of saturated fats. This recommendation follows largely from the observation that saturated fats can raise levels of total serum cholesterol (TC), thereby putatively increasing the risk of atherosclerotic coronary heart disease (CHD). However, TC is only modestly associated with CHD, and more important than the total level of cholesterol in the blood may be the number and size of low-density lipoprotein (LDL) particles that contain it. As for saturated fats, these fats are a diverse class of compounds; different fats may have different effects on LDL and on broader CHD risk based on the specific saturated fatty acids (SFAs) they contain. Importantly, though, people eat foods, not isolated fatty acids. Some food sources of SFAs may pose no risk for CHD or possibly even be protective. Advice to reduce saturated fat in the diet without regard to nuances about LDL, SFAs, or dietary sources could actually increase people's risk of CHD. When saturated fats are replaced with refined carbohydrates, and specifically with added sugars (like sucrose or high fructose corn syrup), the end result is not favorable for heart health. Such replacement leads to changes in LDL, high-density lipoprotein (HDL), and triglycerides that may increase the risk of CHD. Additionally, diets high in sugar may induce many other abnormalities associated with elevated CHD risk, including elevated levels of glucose, insulin, and uric acid, impaired glucose tolerance, insulin and leptin resistance, non-alcoholic fatty liver disease, and altered platelet function. A diet high in added sugars has been found to cause a 3-fold increased risk of death due to cardiovascular disease, but sugars, like saturated fats, are a diverse class of compounds. The monosaccharide, fructose, and fructose-containing sweeteners (e.g., sucrose) produce greater degrees of metabolic abnormalities than does glucose (either isolated as a monomer, or in chains as starch) and may present greater risk of CHD. This paper reviews the evidence linking saturated fats and sugars to CHD, and concludes that the latter is more of a problem than the former. Dietary guidelines should shift focus away from reducing saturated fat, and from replacing saturated fat with carbohydrates, specifically when these carbohydrates are refined. To reduce the burden of CHD, guidelines should focus particularly on reducing intake of concentrated sugars, specifically the fructose-containing sugars like sucrose and high-fructose corn syrup in the form of ultra-processed foods and beverages.

Added fructose: a principal driver of type 2 diabetes mellitus and its consequences

Data from animal experiments and human studies implicate added sugars (eg, sucrose and high-fructose corn syrup) in the development of diabetes mellitus and related metabolic derangements that raise cardiovascular (CV) risk. Added fructose in particular (eg, as a constituent of added sucrose or as the main component of high-fructose sweeteners) may pose the greatest problem for incident diabetes, diabetes-related metabolic abnormalities, and CV risk. Conversely, whole foods that contain fructose (eg, fruits and vegetables) pose no problem for health and are likely protective against diabetes and adverse CV outcomes. Several dietary guidelines appropriately recommend consuming whole foods over foods with added sugars, but some (eg, recommendations from the American Diabetes Association) do not recommend restricting fructose-containing added sugars to any specific level. Other guidelines (such as from the Institute of Medicine) allow up to 25% of calories as fructose-containing added sugars. Intake of added fructose at such high levels would undoubtedly worsen rates of diabetes and its complications. There is no need for added fructose or any added sugars in the diet; reducing intake to 5% of total calories (the level now suggested by the World Health Organization) has been shown to improve glucose tolerance in humans and decrease the prevalence of diabetes and the metabolic derangements that often precede and accompany it. Reducing the intake of added sugars could translate to reduced diabetes-related morbidity and premature mortality for populations.

A population-based study of the relationship between idiopathic hirsutism and metabolic disturbances

PURPOSE

To evaluate the association of idiopathic hirsutism, insulin resistance and metabolic disorders.

METHODS

Participants of this study included 137 women with idiopathic hirsutism and 698 women as controls selected from two large population-based cross-sectional studies including 1,772 reproductive-aged women. Anthropometric and biochemical characteristics of the participants were measured and compared; for instance, insulin resistance was estimated through the homeostatic model assessment and the metabolic syndrome was detected using the Joint Interim Statement.

RESULTS

Mean age, body mass index and other anthropometric measures including waist and hip circumferences were statistically higher in women with idiopathic hirsutism. No differences were observed in blood pressure, glucose and lipid profiles, homeostatic model assessment or the prevalence of insulin resistance, obesity and metabolic syndrome in women with idiopathic hirsutism and controls after adjustment of age and body mass index. In the subgroup of women with metabolic syndrome, fasting glucose levels of those with idiopathic hirsutism were significantly higher than controls, after adjustment of age and body mass index as 114 ± 25.85 vs. 103.52 ± 41.90 mg/dL, P = 0.003. Furthermore, the age and body mass index-adjusted prevalence of impaired fasting glucose in women with idiopathic hirsutism were higher than controls as 16.8 vs. 4.6%, OR = 2.26, 95% CI 1.59-5.38. A threshold of 74.5 cm for waist circumference had the optimal combined sensitivity and specificity for prediction of insulin resistance in women with idiopathic hirsutism, though this value was 90.5 cm for controls.

CONCLUSIONS

Our data suggest that although the overall metabolic characteristics were similar in women with idiopathic hirsutism and controls, glycemic disturbances were more often seen in those suffered from metabolic syndrome and idiopathic hirsutism simultaneously.