The SALT Study
Research type
Research Study
Full title
The effect of increased sodium intake with a carbohydrate-rich meal on glucose homeostasis in subjects without diabetes after bariatric surgery: A proof-of-concept, randomised, open-label, crossover study.
IRAS ID
273999
Contact name
Dimitris Papamargaritis
Contact email
Sponsor organisation
University of Leicester
ISRCTN Number
ISRCTN12008159
Duration of Study in the UK
1 years, 3 months, 1 days
Research summary
Research Summary:
In people without diabetes, symptoms due to low sugar levels (hypoglycaemia) a few hours after eating is a common problem after weight-loss surgery which can be distressing. Currently, there is no good treatment available for this problem.The altered absorption of glucose from the gut after weight-loss surgery seems to be an important factor contributing to hypoglycemia after the meal.Studies in animals after weight-loss surgery have demonstrated that increased salt intake with a meal can modify the absorption of glucose from the gut and increase the glucose levels. If this is also the case in humans, increased salt intake with a meal may be a treatment for post-meal hypoglycemia after weight-loss surgery.
This study will investigate the effect of increased salt intake with a meal on glucose after weight-loss surgery in patients without diabetes. Participants will be randomised to either
Group 1: Standardised MMTT (mixed meal tolerance test) with 2g of table salt at visit 1, followed by standardised meal without additional table salt at visit 2.
Group 2: Standardised MMTT (mixed meal tolerance test) without 2g table salt at visit 1, followed by standardised meal with additional 2g table salt at visit 2.Lay summary of study results:
People without diabetes who have undergone weight loss surgery can sometimes experience low blood sugar (glucose) levels a few hours after eating a meal high in carbohydrates (like sugars and starches). This condition is called post-bariatric hypoglycaemia. It happens because, after surgery, food can move too quickly from the stomach to the intestines, causing carbohydrates to be absorbed too fast. As a result, the body releases too much insulin, a hormone that helps manage blood sugar levels and this leads to a sudden drop in blood sugar levels few hours later.Symptoms of post-bariatric hypoglycaemia can include dizziness, sweating, shaking, hunger, and drowsiness. Current treatments are limited and may include following long-term a low in carbohydrates diet, or even reversing the surgery in more serious cases. There are limited medical treatments for this condition which are not always well tolerated. Because of the lack of effective treatments, more research is needed to find better solutions.
Previous studies in animals (mini-pigs) that have undergone weight loss surgery suggested that adding salt to a carbohydrate-rich meal might help modify how sugar is absorbed in the gut and overall modify blood glucose levels. If this is the case also in humans, it could mean that adding salt might have the potential to improve post-bariatric hypoglycaemia.
In this study, we explored whether adding salt to a carbohydrate-rich meal could improve blood sugar levels after eating in people who had undergone weight loss surgery.
We included 11 adults (4 men and 7 women) who had undergone Roux-en-Y gastric bypass surgery at least one year before the study. None of the participants had been diagnosed with post-bariatric hypoglycaemia.Participants received two different treatments in random order:
• Group One: Participants had a standard meal with 2 grams of added salt for the first treatment, followed by a standard meal without salt for the second treatment.
• Group Two: Participants had a standard meal without salt for the first treatment, followed by a standard meal with 2 grams of added salt for the second treatment.
Blood sugar, insulin, and other hormones secreted from the gut and affecting glucose levels were measured for three hours after each meal to see if adding salt made a difference.Study Findings
When participants ate a standard meal with added salt, their highest blood sugar levels (peak glucose) after the meal were lower compared to when they ate the same meal without salt. However, the added salt did not affect their lowest blood sugar levels (nadir glucose) or their average blood sugar over the three-hour period. There were also no differences in insulin levels or gut hormones between the two treatments.
These results suggest that while adding salt may slightly reduce the peak blood sugar after a meal, it does not significantly impact overall blood sugar control or insulin levels in people who have had weight loss surgery. More research is needed to see if salt could be helpful for those with established post-bariatric hypoglycaemia.REC name
Yorkshire & The Humber - South Yorkshire Research Ethics Committee
REC reference
20/YH/0177
Date of REC Opinion
2 Jul 2020
REC opinion
Further Information Favourable Opinion