Serum magnesium status after gastric bypass surgery in obesity.
BACKGROUND
Roux-en-Y gastric bypass (RYGBP) has become a common surgical procedure to treat morbid obesity. Furthermore, it strongly reduces the incidence of type 2 diabetes and mortality. However, there is scant information on how magnesium status is affected by RYGBP surgery. Previous bariatric surgery methods, like jejunoileal bypass, are associated with hypomagnesemia.


METHODS
Twenty-one non-diabetic morbidly obese patients who underwent RYGBP were evaluated before and 1 year after surgery and compared to a matched morbidly obese control group regarding serum magnesium. Groups were matched regarding weight, BMI, abdominal sagittal diameter and fasting glucose, blood pressure, and serum magnesium concentrations before surgery in the RYGBP group.


RESULTS
The serum magnesium concentrations increased by 6% from 0.80 to 0.85 mmol/l (p = 0.019) in the RYGBP group while a decrease by 4% (p = 0.132) was observed in the control group. The increase in magnesium concentration at the 1-year follow-up in the RYGBP group was accompanied by a decreased abdominal sagittal diameter (r (2) = 0.32, p = 0.009), a lowered BMI (r (2) = 0.28, p = 0.0214), a lowered glucose concentration (r (2) = 0.28, p = 0.027) but not by a lowered insulin concentration (p = 0.242), a lowered systolic (p = 0.789) or a lowered diastolic (p = 0.785) blood pressure.


CONCLUSIONS
RYGBP surgery in morbidly obese subjects is characterized by reduced visceral adiposity, lowered plasma glucose, and increased circulating magnesium concentrations. The inverse association between lowered central obesity, lowered plasma glucose and increased magnesium concentrations, needs further detailed studies to identify underlying mechanisms.
Johansson
Hans-Erik
HE
Department of Public Health and Caring Sciences/Geriatrics, Uppsala University, Uppsala Science Park, Uppsala 75185, Sweden. hans-erik.johansson@akademiska.se
Zethelius
Björn
B
Ohrvall
Margareta
M
Sundbom
Magnus
M
Haenni
Arvo
A
D000328:Adult; D001786:Blood Glucose / Q000378:metabolism; D015992:Body Mass Index; D005260:Female; D005500:Follow-Up Studies; D015390:Gastric Bypass; D006801:Humans; D007328:Insulin / Q000097:blood; D050152:Intra-Abdominal Fat; D008274:Magnesium / Q000097:blood*; D008297:Male; D008875:Middle Aged; D009767:Obesity, Morbid / Q000097:blood* / Q000601:surgery*; D013997:Time Factors
D001786:Blood Glucose; D007328:Insulin; D008274:Magnesium