Cardiovascular Impact of 10 Year Lifestyle Interventions In Diabetics

A recent study has found that lifestyle interventions and significant weight reduction among diabetes patients can be maintained for up to 10 years in real-world clinical practice.

Investigators presented the results of the 10-year real-world study into the impact of intensive lifestyle intervention on cardiovascular risk factors in patients with diabetes at the American Diabetes Association (ADA) 2019 Scientific Sessions in San Francisco, CA.

The study examined 129 patients with diabetes and obesity who were enrolled in a 12-week intensive lifestyle intervention program called Why WAIT. At year 1, participants were divided into 2 groups: Group A was those who achieved less than 7% weight loss (61 patients, 47.3%) and group B was those who maintained greater than 7% weight loss (68 patients, 52.7%).

The total study population lost on average 10.8±4.6 kg (-9.7%) at 12 weeks and maintained an average weight loss of 7.7±10 Kg (-6.9%) at 10 years. At 10 years, group A maintained 4.3±9.5 kg (-4.3%) and group B maintained 10.8±9.3 Kg (-9.3%) of weight loss.

The A1C in group A decreased from 7.5±1.3% to 6.7±0.9% at 12 weeks, but increased to 7.7±1.4% at one year and 8.0±1.9% at 10 years. In group B, A1C decreased from 7.4±1.2% to 6.4±0.9% at 12 weeks and rose to 6.8±1.2% at one year and 7.3±1.5% at 10 years.

Investigators noted that despite weight regain, group A maintained significant improvements in LDL and HDL cholesterol and had no change in blood pressure, but significant worsening of serum triglycerides at 10 years. Group B maintained improvements in lipid profile and had a serum triglycerides increase that was considered non-significant at 10 years, but had lower blood pressure for the initial 18 months.

Study investigator Osama Hamdy, MD, PhD, medical director of obesity clinical program at Joslin Diabetes Center, sat down with MD Magazine® at ADA 2019 to discuss the results of the study.

MD Mag: What were the methods, findings, and clinical implications of your study into 10-year impact of lifestyle interventions?

Hamdy: Initially, people are always pessimistic that lifestyle intervention will not work in real-world clinical practice and our program, which is called Why Wait program, is the first translational to be implemented in real-world clinical practice. So, patients that we see and you see every single day in your practice. We did the program in 2005, the results were very encouraging after 12 weeks of the program. Then everyone said show us how this can be maintained for a year, 2 years, 3 years, up to 10 years. the data that we presented today is 10 years of follow-up of people who did the program between 2005 and 2008.

The number that we hit in the program, that were followed was 128 patients, who did the program and completed 12 weeks of the program. Then we divided them after 1 year to a group that sustained weight loss more than 7% and a group who regained weight and didn't achieve 7% weight loss. The whole idea is what would happen on cardiovascular risk outcomes, what would happen with a1c, what would happen with microvascular complications. If you would sustain weight loss or you were to regain weight back, because you know that almost 50% regain weight back, another 50% maintain weight loss. So, if you take them all together and you evaluate them on a yearly basis — and that's what we did, we evaluate them every year — and we continued to follow them for the entire 10 years, measuring their a1c, their weight, their lipid profile, their blood pressure, and also we search for all diagnoses of microvascular complications — diabetic nephropathy, diabetic retinopathy, and insulin diabetic neuropathy as well.

First of all, you have to be optimistic that weight loss can be achieved and can be maintained for a long duration. That's number one. If you don't believe it, you won't translate this to your patients. So, the data that we showed, showed that people can maintain weight loss for 10 years with an average of 6.9%. So, imagine 7% weight loss maintained for 10 years — not only that, the group that lost and maintained weight loss more than 7% in the first year were able to maintain 9.3% at the end of 10 years. So, you can imagine this is a marked improvement.

So, people usually ask what is the secret. How do those people maintain weight loss and how people achieve the weight loss to start this and my answer is the whole motive of Why WAIT program is based on one very important concept: how I can maintain your muscle mass, lean body mass for longer duration? So, this is not like any other program that took people and asked them to run on a treadmill or to walk 10,000 steps or gives them just a low-calorie diet but what we did is we give them a meal that is higher in protein, we give them lower carbohydrates in the meal — no more than 40-45% with lower glycemic index but with higher protein, 112.5 grams per kilogram. Then we asked them to do more strength exercises, like bodybuilding, so you build the muscles. Usually when you lose weight, 25 to 27% of the weight loss is from your muscles.

So, your energy expenditure goes down, your basal metabolic rate goes down so what happens here, we were able to maintain weight loss so instead of 27% weight loss from muscle mass only 9% of the weight loss is from muscle mass. Now you are keeping your energy expenditure high, keeping the basal metabolic rate high and based on that people maintained weight loss for longer duration.

So, the whole idea here from, all our research, is how I can keep your muscle mass up during weight loss and it paid off, even for people who gain weight back it was a big surprise their lipid profile still improved — even if they regained weight back after 10 — so it is exciting. The other two observations that we had seen are very important in clinical practice. One is related to the incidence of nephropathy. We usually say that at the time of diagnosis kidneys is downhill but it looks like lifestyle and weight loss can improve the kidney function and can reduce incidence of diabetic nephropathy. While seeing some improvement but not statistical significant in retinopathy and neuropathy. Nephropathy definitely is some good change.