Diabetes diet may lower blood pressure, reducing need for drugs

  • In a study of people with type 2 diabetes and obesity on a low energy replacement diet within a structured intensive weight loss program, 28% of participants could stop blood pressure medication for at least 2 years.
  • The main adverse reaction that participants reported were mild to moderate dizziness.
  • Researchers concluded that long-term support is essential to maintain weight loss.

Diabetes is a common and serious medical condition, affecting approximately 463 million people worldwide in 2019. People with a condition called metabolic syndrome are about five times more likely to develop type 2 diabetes.

Metabolic syndrome consists of a constellation of clinical findings defined by the presence of at least three of the following:

  • elevated blood pressure (hypertension)
  • abdominal obesity
  • impaired glucose tolerance
  • insulin resistance,
  • increased triglycerides
  • low high-density lipoprotein cholesterol (“good cholesterol”)

People who develop type 2 diabetes have a greater chance of having a heart attack, stroke, chronic kidney disease, nerve damage (neuropathy), and eye disease (retinopathy).

Approximately 85% of patients with type 2 diabetes will require treatment for high blood pressure. Although antihypertensive medication medications effectively decrease blood pressure, some medications, such as β-blockers and thiazide diuretics, may have side effects or aggravate blood glucose control.

The American Diabetes Association estimates that 33–49% of people with diabetes fail to achieve blood glycemic, blood pressure, and blood lipid goals. Lifestyle modifications, such as weight loss, can help.

Weight loss can effectively reduce blood pressure by about 1 millimeter of mercury (mmHg) for each kilogram (kg) of weight lost. However, current clinical practice guidelines do not recommend a trial withdrawal of antihypertensive medication during a medically managed weight loss program for people with diabetes who have overweight.

In the Diabetes Remission Clinical Trial (DiRECT), researchers at the Universities of Glasgow and Newcastle in the United Kingdom demonstrated that the primary-care-driven intensive weight management program Counterweight-Plus resulted in remission of type 2 diabetes in 46% of participants at 12 months.

During the initial total diet replacement phase, participants underwent a planned withdrawal of all blood pressure medication to prevent low blood pressure when standing up from sitting or lying down.

Researchers re-examined data from this study to determine the safety of stopping blood pressure medications and the extent of the decrease in blood pressure levels in participants with and without hypertension. The scientists recently published the results from this post-hoc analysis in the journal Diabetologia.

Significant blood pressure decrease

The study used a low energy (825–853 kilocalories per day) formula diet for 12–20 weeks in the intervention part of the study, followed by a step-wise reintroduction of food over 2–8 weeks, as well as a structured weight-loss maintenance program with monthly visits.

Participants receiving the intervention discontinued all diabetes and antihypertensive medications when starting the initial total diet replacement phase unless they needed them for conditions other than diabetes or hypertension.

Researchers monitored blood pressure and glycemic levels throughout the study and reintroduced medication to those participants whose levels increased.

78 of the 143 participants receiving total diet replacement had hypertension at baseline, with 44% of participants receiving one antihypertensive drug and approximately 56% receiving two or more. Around 36% of participants reported dizziness during the total diet replacement phase.

The study demonstrated significant decreases in average blood pressure levels during total diet replacement therapy at 20 weeks and 1 and 2 years. In those participants with no history of hypertension, the decreases were immediate. In contrast, significant reductions in blood pressure did not occur for those previously treated for hypertension until about week 9.

During the total diet replacement phase, 27.5% of participants (26% on one medication and 74% on two or more medications had to restart taking antihypertensive medications. However, at 2 years, 28% of the participants who stopped antihypertensive drugs did not need to take them again.

According to the study, 53 people saw remission in their type 2 diabetes with an average weight loss of 11.4 kg at 2 years. Of this group, 27 participants had high blood pressure and stopped all blood pressure medication at baseline, with 12 remaining off all antihypertensive medication at 2 years.

Strengths and limitations of the study

Dr. Roy Taylor, joint principal investigator, co-senior author, and Professor of Medicine and Metabolism at the Magnetic Resonance Centre Campus for Ageing and Vitality in Newcastle upon Tyne, commented on the strengths of the study to Medical News Today.

“Firstly,” he said, “the study was a randomized controlled trial that can provide the highest standard of information to guide doctors. Secondly, primary care nurses (or dietitians if available) managed the individual patients, releasing valuable time for doctors to manage other patients.”

“Thirdly, the large numbers of patients with type 2 diabetes involved in DiRECT were entirely representative of all people with this condition, including equal representation of all socio-economic groups. Fourthly, this contributes to decreasing health care costs.”

Limitations of the study include its open-label design and use of post-hoc analysis. Although post-hoc analysis can help identify data not shown by the study’s primary objective, researchers cannot make definitive conclusions from post-hoc analyses, only hypotheses for further study.

Furthermore, the trial participants had a type 2 diabetes duration of only 3 years on average, limiting the generalizability of results to those with long-standing type 2 diabetes.

Further research is needed to delineate which patients with type 2 diabetes would benefit most from this intensive weight management intervention and the long-term durability of response.

Dr. Roy Taylor also commented on the implications of the study results, saying, “Many people do not like taking tablets, not least because of side effects.”

“At present, they are told that there is no alternative. The paper proves that substantial weight loss can remove the need for blood pressure tablets or decrease the number and type of tablets taken. Also, the motivation for undertaking substantial weight loss is to escape from the ‘life sentence’ of type 2 diabetes, and this paper demonstrates that there are other major benefits to this.”

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