Differences between HbA1c and glucose-related variables in predicting weight loss and glycaemic changes in individuals with overweight and hyperglycaemia - The PREVIEW trial.

AIMS: To examine the differences between HbA1c and glucose related variables in predicting weight loss and glycaemic changes following 8 weeks of low energy diet (LED) in individuals with overweight and hyperglycaemia. RESEARCH DESIGN AND METHODS: 2178 individuals with ADA-defined pre-diabetes - impaired fasting glucose (IFG) and/or impaired glucose tolerance (IGT) - who started an 8 week LED weight loss diet, were included in this analysis. Participants were enrolled in the PREVIEW (PREVention of diabetes through lifestyle interventions and population studies In Europe and around the World) clinical trial. Multivariable linear mixed effects regression models and generalised additive mixed effect logistic models were used. RESULTS: Only 1 in 3 participants (33%) had HbA1c levels defined as pre-diabetes. Neither baseline HbA1c, IFG or IGT were associated with body weight change at 8 weeks. Higher baseline body weight, baseline fasting insulin and weight loss predicted normalisation of fasting plasma glucose (FPG), whilst higher baseline fasting insulin, C-reactive protein (hsCRP) and older age predicted normalisation of HbA1c. Additionally, male sex and higher baseline BMI, body fat and energy intake were positively associated with weight loss, whereas greater age and higher HDL-cholesterol predicted less weight loss. CONCLUSIONS: Whilst neither HbA1c nor fasting glucose predicts short-term weight loss success, both may impact the metabolic response to rapid weight loss. We propose a role of inflammation versus total body adiposity since these variables are independent predictors of the normalisation of HbA1c and fasting glucose, respectively.

Higher Protein Intake Is Not Associated with Decreased Kidney Function in Pre-Diabetic Older Adults Following a One-Year Intervention-A Preview Sub-Study.

Concerns about detrimental renal effects of a high-protein intake have been raised due to an induced glomerular hyperfiltration, since this may accelerate the progression of kidney disease. The aim of this sub-study was to assess the effect of a higher intake of protein on kidney function in pre-diabetic men and women, aged 55 years and older. Analyses were based on baseline and one-year data in a sub-group of 310 participants included in the PREVIEW project (PREVention of diabetes through lifestyle Intervention and population studies in Europe and around the World). Protein intake was estimated from four-day dietary records and 24-hour urinary urea excretion. We used linear regression to assess the association between protein intake after one year of intervention and kidney function markers: creatinine clearance, estimated glomerular filtration rate (eGFR), urinary albumin/creatinine ratio (ACR), urinary urea/creatinine ratio (UCR), serum creatinine, and serum urea before and after adjustments for potential confounders. A higher protein intake was associated with a significant increase in UCR (p = 0.03) and serum urea (p = 0.05) after one year. There were no associations between increased protein intake and creatinine clearance, eGFR, ACR, or serum creatinine. We found no indication of impaired kidney function after one year with a higher protein intake in pre-diabetic older adults.