Insulin Resistance

Importance: Type 2 diabetes involves progressive loss of insulin secretion from pancreatic β cells in the setting of insulin resistance and manifests clinically as hyperglycemia. Type 2 diabetes accounts for 90% to 95% of all cases of diabetes globally, with estimates ranging from 589 million to 828 million people worldwide. In the US, type 2 diabetes affects approximately 1 in 6 adults.

Observations: Risk factors for type 2 diabetes include older age, family history, overweight or obesity, physical inactivity, gestational diabetes, Hispanic ethnicity, and American Indian or Alaska Native, Asian, or Black race. Diabetes is diagnosed if fasting plasma glucose is greater than or equal to 126 mg/dL, hemoglobin A1C is greater than or equal to 6.5%, or 2-hour glucose during 75-g oral glucose tolerance testing is greater than or equal to 200 mg/dL. Approximately one-third of adults with type 2 diabetes have cardiovascular disease and 10.1% have severe vision difficulty or blindness. The prevalence of type 2 diabetes is 39.2% among patients with kidney failure. Although weight management is an important component of treatment for type 2 diabetes, no specific diet has been proven to be most effective for improving health outcomes. Physical activity can reduce hemoglobin A1C by 0.4% to 1.0% and improve cardiovascular risk factors (ie, hypertension and dyslipidemia). Randomized clinical trials have reported absolute reductions in microvascular disease (3.5%), such as retinopathy and nephropathy, myocardial infarction (3.3%-6.2%), and mortality (2.7%-4.9%), with intensive glucose-lowering strategies (hemoglobin A1C <7%) vs conventional treatment 2 decades after trial completion. First-line medications for type 2 diabetes include metformin and, in patients with cardiovascular or kidney comorbidities or at high cardiovascular risk, glucagon-like peptide-1 receptor agonists (GLP-1RAs) or sodium-glucose cotransporter 2 inhibitors (SGLT2is). Common add-on medications include dual glucose-dependent insulinotropic polypeptide (GIP)/GLP-1RAs, dipeptidyl peptidase-4 inhibitors, sulfonylureas, and thiazolidinediones. Approximately one-third of patients with type 2 diabetes require treatment with insulin during their lifetime. Several randomized clinical trials have demonstrated benefits of specific SGLT2i and GLP-1RA medications compared with placebo for atherosclerotic cardiovascular disease (12%-26% risk reduction), heart failure (18%-25% risk reduction), and kidney disease (24%-39% risk reduction) over 2 to 5 years. Most trial participants with type 2 diabetes were taking metformin. High-potency GLP-1RA and dual GIP/GLP-1RA medications result in weight loss of greater than 5% in most individuals with type 2 diabetes, and weight loss may exceed 10%.

Conclusions: Type 2 diabetes affects up to 14% of the global population and is associated with preventable long-term complications, such as cardiovascular disease, kidney failure, vision loss, and increased mortality. In addition to lifestyle modifications including diet, exercise, and weight management, metformin is generally first-line therapy for attainment of hemoglobin A1C targets. For individuals with type 2 diabetes and cardiovascular or kidney disease or at high cardiovascular risk, guidelines recommend early treatment with SGLT2i and/or GLP-1RA medications.

Author/s:

Rita R Kalyani, Joshua J Neumiller, Nisa M Maruthur, Deborah J Wexler

Effects of weight loss during a very low carbohydrate diet on specific adipose tissue depots and insulin sensitivity in older adults with obesity: a randomized clinical trial

Brian Desmarais — Tue, 25 Aug 2020 16:39:54 +0000

Date Added:

August 25, 2020

Journal/Publication:

Nutrition & Metabolism

Publication Date:

August 12, 2020

URL:

Effects of weight loss during a very low carbohydrate diet on specific adipose tissue depots and insulin sensitivity in older adults with obesity: a randomized clinical trial

Type:

Clinical Research Results

Format:

Article

DOI (1):

10.1186/s12986-020-00481-9

MeSH

Absorptiometry, Photon

Glucose Clamp Technique

obesity

Body Composition

Carbohydrate-Restricted

This short-term (8-week) RCT found that 60-75 years old adults with obesity lost a lot more weight and visceral adipose tissue and increased their insulin sensitivity more when following a low carbohydrate diet than when following a low fat diet. James W. Mold, MD, MPH

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Background: Insulin resistance and accumulation of visceral adipose tissue (VAT) and intermuscular adipose tissue (IMAT) place aging adults with obesity at high risk of cardio-metabolic disease. A very low carbohydrate diet (VLCD) may be a means of promoting fat loss from the visceral cavity and skeletal muscle, without compromising lean mass, and improve insulin sensitivity in aging adults with obesity.

Objective: To determine if a VLCD promotes a greater loss of fat (total, visceral and intermuscular), preserves lean mass, and improves insulin sensitivity compared to a standard CHO-based/low-fat diet (LFD) in older adults with obesity.

Design: Thirty-four men and women aged 60-75 years with obesity (body mass index [BMI] 30-40 kg/m2) were randomized to a diet prescription of either a VLCD (< 10:25:> 65% energy from CHO:protein:fat) or LFD diet (55:25:20) for 8 weeks. Body composition by dual-energy X-ray absorptiometry (DXA), fat distribution by magnetic resonance imaging (MRI), insulin sensitivity by euglycemic hyperinsulinemic clamp, and lipids by a fasting blood draw were assessed at baseline and after the intervention.

Results: Participants lost an average of 9.7 and 2.0% in total fat following the VLCD and LFD, respectively (p < 0.01). The VLCD group experienced ~ 3-fold greater loss in VAT compared to the LFD group (- 22.8% vs - 1.0%, p < 0.001) and a greater decrease in thigh-IMAT (- 24.4% vs - 1.0%, p < 0.01). The VLCD group also had significantly greater thigh skeletal muscle (SM) at 8 weeks following adjustment for change in total fat mass. Finally, the VLCD had greater increases in insulin sensitivity and HDL-C and decreases in fasting insulin and triglycerides compared to the LFD group.

Conclusions: Weight loss resulting from consumption of a diet lower in CHO and higher in fat may be beneficial for older adults with obesity by depleting adipose tissue depots most strongly implicated in poor metabolic and functional outcomes and by improving insulin sensitivity and the lipid profile.

Trial registration: NCT02760641. Registered 03 May 2016 - Retrospectively registered.

Author/s:

Gower, Babara, Goss, Amy, Soleymani, Taraneh, Stewart , Mariah, Pendergrass, May, Lockhart, Mark, Kranz, Olivia, Dowla, Shima, Bush, Nikki, Barry, Valene Garr, Fontaine, Kevin R.

The effects of sleep extension on cardiometabolic risk factors: A systematic review

Brian Desmarais — Wed, 19 Jun 2019 20:20:01 +0000

Date Added:

June 19, 2019

Journal/Publication:

The Journal of Sleep Research

Publisher:

European Sleep Research Society

Publication Date:

June 5, 2019

URL:

The effects of sleep extension on cardiometabolic risk factors: A systematic review.

Type:

Meta-analyses, Reviews, and Guidelines

Format:

Article

DOI (1):

https://doi.org/10.1111/jsr.12865

Keywords

cardiovascular disease

insulin sensitivity

metabolic syndrome

non-communicable diseases

MeSH

cardiovascular diseases

overweight

Noncommunicable Diseases

Sugars

Insulin Resistance

risk factors

This systematic review found that increasing sleep duration improves direct and indirect measures of insulin sensitivity,

decreased leptin and peptide tyrosine‐tyrosine, and reductions in overall appetite, desire for sweet and salty foods, intake of daily free sugar, and percentage of daily

caloric intake from protein. James W. Mold, MD, MPH

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Studies have shown bidirectional relationships between short- or long-sleep duration and risk for obesity, non-communicable diseases, all-cause mortality and cardiovascular disease mortality. Increasing sleep duration may be an appropriate strategy to reduce cardiometabolic riskin short-sleeping individuals. The aim is to review the effects of sleep extension interventions on cardiometabolic risk in adults. The PubMed and Scopus databases were searched for relevant, English, peer-reviewed scientific publications (until August 2018). Seven studies that aimed to increase sleep duration in adults by any sleep extension intervention and described at least one cardiometabolic risk factor were included. These studies had a combined sample size of 138 participants who were either healthy (n = 14), healthy short-sleeping (n = 92), overweight short-sleeping (n = 10), or pre- or hypertensive short-sleeping (n = 22) individuals. The durations of the sleep extensioninterventions ranged from 3 days to 6 weeks, and all successfully increased total sleep time by between 21 and 177 min. Sleep extensionwas associated with improved direct and indirect measures of insulin sensitivity, decreased leptin and peptide tyrosine-tyrosine, and reductions in overall appetite, desire for sweet and salty foods, intake of daily free sugar, and percentage of daily caloric intake from protein. This review provides preliminary evidence for a role for sleep extension to improve cardiometabolic outcomes and directive towards future studies in the field of cardiometabolic health and sleep.

Author/s:

Henst, R.H.P., Pienaar, P.R., Roden, L.C., Rae, D.E.