New dietary supplement study? (L-arginine)

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Expand view Topic review: New dietary supplement study? (L-arginine)

Re: New dietary supplement study? (L-arginine)

Post by caryn » Fri May 20, 2011 11:11 pm

Actually I hate "can't hurt might help", because that's what they said about supplementing vitamins C and E, and then the huge expensive multicenter trial turned up that, oops, actually, innocuous vitamins can hurt you.

I have not seen the full-text yet but there has been preliminary work into l-arginine because it inhibits nitric oxide synthase, which is the same pathway that cigarettes are affecting. One oddity is that our l-arginine levels are already higher than that of pregnant controls.

Nitric oxide (NO), which is synthesized from L-arginine in endothelial cells by the endothelial nitric oxide synthase (eNOS), provides a tonic dilator tone and regulates the adhesion of white blood cells and platelet aggregation. Alterations in the L-arginine-NO pathway have been associated with the development of PE. Various studies, reporting decreased, elevated or unchanged levels of nitrite (NO(2)) and nitrate (NO(3)), two end products of NO metabolism, have been published. Our group contributed to those contradictory reports describing cases of PE with both elevated and decreased levels of NO(2) and NO(3). Apparently, diminished levels of NO could be related to deficiencies in the ingestion of dietary calcium associated to low levels of plasma ionic calcium, which is crucial to the eNOS' activity. Also, low levels of NO could be associated with the presence of eNOS polymorphisms or the presence of increased levels of ADMA, the endogenous inhibitor of NO. High levels of NO associated to low levels of cGMP suggest a decreased bioactivity of NO, which is probably related to an increased degradation of NO caused by a high production of superoxide in states of infection and inflammation.

The BP changes after 10-12 weeks of treatment did not differ between groups. A lower percentage of women received antihypertensive drugs in the L-Arg group than the placebo group. The incidence of superimposed preeclampsia indicated delivery before the 34th weeks and certain neonatal complications tended to be higher in the placebo group.

We found that not only maternal concentrations of ADMA and SDMA but also l-arginine were significantly higher in women with preeclampsia than in controls. In fetal samples, only SDMA concentrations were higher in the preeclampsia group than in controls. The median ADMA concentration was three times higher in the fetal circulation than in the maternal circulation, but there was no difference between the preeclampsia group and the control group, and the veno-arterious gradient indicated that the placenta was the source of ADMA.

Cigs also cause pregnancy problems, so the trick with anything working on that pathway is whether or not the positives outweigh the negatives. There are a few big new papers out on this idea and a trial in progress so we'll see where this goes...

Re: New dietary supplement study? (L-arginine)

Post by kerisue » Fri May 20, 2011 04:22 pm

I hadn't seen that particular study, but I have seen some other positive research about l-arginine. I haven't seen anything negative about it, at least as it relates to preeclampsia. I've asked 2 MFMs about using it and both said something like, "not sure how much good that will do but it won't hurt."

New dietary supplement study? (L-arginine)

Post by ilovepie » Fri May 20, 2011 01:09 pm

I looked around a bit and didn't see anything that was obviously about this study:

Has there been discussion yet? Caryn? :)