Short cycles of very low calorie diet in the therapy of obese type II diabetes mellitus

The Prevention Of WEight Regain in diabetes type 2 (POWER) study: the effectiveness of adding a combined psychological intervention to a very low calorie diet, design and pilot data of a randomized controlled trial

Background

Obesity is of major pathogenetic importance to type 2 diabetes, it contributes to poor glycemic control and increases the risk of cardiovascular disease. Over 80% of patients with diabetes type 2 are overweight. To achieve a more favourable risk profile, changes in diet and lifestyle are needed. However, current treatment programs for obese DM type 2 patients are not effective in the long term. In this RCT, we compare the effectiveness of a Combined Psychological Intervention (CPI) and usual care in maintaining the favourable effects on weight and risk profile during 2 years of follow-up after a Very Low Calorie Diet (VLCD).

Methods and design

In a randomised parallel group intervention study, 140 patients with type 2 diabetes and overweight (BMI>27 kg/m2) will be recruited from the outpatient department of the Erasmus Medical Centre.

After obtaining ≥5% of weight loss with a VLCD, participants will be randomly assigned to CPI or usual care for 10 weeks. CPI consists of cognitive behaviour therapy, problem solving therapy and proactive coping.

Primary outcome measure is weight change (kg).

Other outcome measures are Body Mass Index (BMI = weight (kg)/length (m)2), waist circumference (cm), systolic blood pressure (mmHg), HbA1c (mmol/mol), lipid levels (LDL, HDL, TG (mmol/l) and chol/HDL-ratio), antidiabetic agents and doses, cardiovascular risk profile (UKPDS), lifestyle and quality of life (EuroQol EQ-5D). Psychosocial parameters are also studied, as secondary outcomes as well as determinants for weight loss.

When successful, we want to conduct an analysis of the cost effectiveness of the intervention as compared to usual care.

Discussion

We expect that a CPI after a VLCD will be effective in maintaining weight loss and improving cardiovascular risk and glycaemic control, while being cost-effective and improving quality of life in patients with type 2 diabetes.

Clinical trials registration

trialregister.nl NTR2264

Current status of bariatric surgery in the treatment of type 2 diabetes

Bariatric surgery (from the Greek words baros meaning 'weight' and iatrikos 'the art of healing') is a rapidly evolving branch of surgical science. The aim is to induce major weight loss in those whose obesity places them at high risk of serious health problems. In an attempt to balance the risks of surgery against the benefits of weight loss, bariatric operations are currently performed only in the morbidly obese, or those with a body mass index (BMI) > 35 kgm(-2) who already have developed comorbidity such as type 2 diabetes. Although weight loss is beneficial for obese patients with diabetes, current medical treatment for obesity is difficult. In contrast, observational studies show a major impact of bariatric surgery on diabetes, raising the question whether this approach should be used more widely to treat diabetes in obese patients? If bariatric surgery were shown to be the best way to treat diabetes in obese subjects the implications for health services would be wide-ranging. Bariatric surgery leads to withdrawal of diabetic treatment in about 60% or more of patients, and reductions of therapy for many others. Although data on bariatric surgery in subjects with diabetes are provocative, most studies have been uncontrolled or flawed in other ways. Most importantly, bariatric surgery has not yet been compared against standard medical treatment for diabetes in randomized controlled trials with diabetes-specific endpoints in all relevant patient groups. Potential indications for bariatric surgery are discussed, and the unanswered questions that need to be addressed by clinical trials are summarized. Although small numbers of patients may be interested in bariatric surgery for type 2 diabetes, current data are insufficient to endorse its wide scale use for this indication. Until essential studies are undertaken the role and economics of bariatric surgery in the diabetic clinic will remain uncertain.

Very low calorie diet (VLCD): a useful alternative in the treatment of the obese NIDDM patient

Conventional treatment of obese noninsulin dependent diabetes mellitus (NIDDM) patients is often unsatisfactory. In this study the efficacy of Modifast, a commercial very low calorie diet (VLCD), was evaluated in a population of obese poorly controlled NIDDM patients. The mechanisms of action of VLCD in these patients were also studied by comparing: (i) Plasma insulin and glucose profiles after a VLCD and an isocaloric mixed meal and (ii) plasma amino acid levels, both at baseline and after four weeks of VLCD treatment. A total of 14 obese NIDDM patients (M/F 7/7. median body mass index (BMI) 38.7 kg-2, interquartile range (IQ) 34.7-46.5 kg-2, waist circumference 116 cm, IQ 106-139 cm, insulin treated 7/14) with poor diabetic control (HbA1c 8.6%, IQ 7.8-10%) were studied. Patients were given a VLCD (425 kcal/day) for 12 weeks. At baseline, VLCD and isocaloric meal tests were performed on consecutive mornings. Fasting plasma amino acid levels were also determined at baseline and after 4 weeks of VLCD treatment. Weight, waist circumference, HbA1c, blood pressure, fasting plasma insulin, total cholesterol and triglyceride levels all fell significantly following VLCD treatment. Insulin therapy was able to be ceased in the seven insulin treated patients. Oral hypoglycaemic agent dosage fell from a median of eight (IQ 6-12) to two (IQ 0-8) tablets per day (P = 0.03) in patients initially on this form of therapy. Insulin secretion was higher after VLCD than isocaloric meal (P = 0.04). Fasting plasma alanine level fell from 512.0 (IQ 412.0-563.0) to 374.0 (IQ 342-472.0) mumol/l (P = 0.04) following VLCD treatment. In conclusion, the short term use of a VLCD is very effective in rapidly improving glycaemic control and promoting substantial weight loss in obese NIDDM patients. Moreover, a VLCD diet increases insulin secretion and reduces substrate for gluconeogenesis. Thus, VLCD treatment may improve glycaemic control by factors more than caloric restriction alone.

Sertraline enhances the effects of cognitive-behavioral treatment on weight reduction of obese patients

Serotonin reuptake inhibitors, such as dexfenfluramine, fluoxetine and fluvoxamine, have been proposed as therapeutical tools for the treatment of eating disorders and obesity. Sertraline, a SSRI used in the treatment of depression, interferes with eating behavior in animal models, but it has not been tested in obese humans. Aim of this study is the assessment of the effects of sertraline on eating attitudes and body weight in obese patients with and without mood disorders. A consecutive series of 65 obese out-patients aged 18-65 years, with a body mass index (BMI) > 30 kg/m2, was treated for 6 months with sertraline 150 mg/day per os, in addition to a cognitive-behavioral treatment (CBT). A consecutive series of 60 obese patients with similar characteristics, who were treated with CBT only, were used as control group. A greater reduction of BMI (mean +/- SD) was observed in sertraline-treated patients when compared to controls (from 35.3 +/- 5.7 to 32.0 +/- 5.4 kg/m2 in sertraline-treated patients, from 37.1 +/- 7.0 to 36.0 +/- 7.1 kg/m2 in controls; 6.5 +/- 5.4% vs. 3.0 +/- 6.3%; p < 0.01), while a similar change in eating attitudes (evaluated through the BITE questionnaire) was observed in both groups. Effects of sertraline on eating attitude and body weight were similar in patients with and without mood disorders. In conclusion, sertraline, administered together with CBT, seems to be more effective in inducing weight loss in obese patients when compared with CBT alone, and therefore it could be a useful tool in the first months of CBT for severe obesity.

Therapeutic challenges in the obese diabetic patient with hypertension

Obesity, diabetes mellitus, and hypertension are common and interrelated medical problems in Westernized, industrialized societies. These medical conditions are associated with an increased risk of cardiovascular disease and are more prevalent among minorities, such as African-American and Hispanic populations. The associated cardiovascular risks of these problems are more thoroughly addressed in another review in this supplement. Obesity markedly enhances the development of type II diabetes. Moreover, it enhances the cardiovascular risk associated with other risk factors, such as hypertension and dyslipidemia. Weight reduction in association with an aerobic exercise program improves metabolic abnormalities and reduces blood pressure in individuals with diabetes and hypertension. Frequently, however, pharmacologic treatment is required to lower blood pressure. Individual therapy with an angiotensin-converting enzyme (ACE) inhibitor is preferred initially in these individuals, with the addition of either a low dose diuretic or a nondihydropyridine calcium antagonist if additional blood pressure reduction is required. These additive agents are recommended, since each has been shown individually to reduce cardiovascular morbidity and to preserve renal function among diabetic patients. Other issues, such as aggressive therapy of lipids and adequate glycemic control, are also important strategies for reducing cardiovascular and renal morbidity and mortality in this very high-risk population.