| Bariatric Surgery information Lap-Band Surgery: Homocysteine Levels, Folate and Vitamin B12 |
Review of Plasma Homocysteine After Lap Band Obesity Surgery |
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Weight Loss Surgery Information - Bariatric Research Studies |
Elevated homocysteine levels with weight
loss after Lap-Band surgery:
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Method
We measured levels of fasting plasma homocysteine (tHcy), folate (serum and RBC) and vitamin B12 in two groups. The study group was 293 consecutive patients at 12 (n=192) or 24 (n=101) months review after surgery. The controls were 244 consecutive patients presenting for this surgery.
Result
The group losing weight had higher geometric mean tHcy levels: 10.4 (95% CI, 9.8-10.8) micromol/l compared with 9.2 (95% CI, 8.9-9.7) in controls. This occurred with higher folate levels and unchanged vitamin B12 levels. Levels of folate and B12 together explained 35% (r (2)) of the homocysteine variance in the weight loss group compared with only 9% (r (2)) in controls. Those taking regular multivitamin supplements had lower tHcy levels: 9.6 micromol/l vs 12.3 in those not taking supplements. A low normal plateau of tHcy levels occurred at levels of folate >15 ng/l and B12)600 ng/ml. A curvilinear relationship exists between these cofactors and tHcy levels, with the dose-response relationship shifted to the right in the weight loss group.
Conclusion
This study shows elevated tHcy levels with weight loss, without lower serum folate or vitamin B(12) levels. There is an altered dose-response relationship with higher serum B(12) and folate levels required to maintain recommended tHcy levels. Patients losing weight have significant health benefits; however, they may be at greater risk of vascular events or fetal abnormality in association with raised tHcy levels. Multivitamin supplementation is effective in lowering tHcy levels.
Source:
Dixon JB, Dixon ME, O'Brien PE. Monash University Department of Surgery,
Alfred Hospital, Melbourne, Victoria, 3181 Australia. 2001