Comparison of biomarker for diagnosis of nitrous oxide abuse: challenge of cobalamin metabolic parameters, a retrospective study.

BACKGROUND: Recreational use of nitrous oxide (N2O) leads to neurological disorders including combined subacute degeneration of spinal cord, psychological disorders, and thrombosis. Serum or urine N2O assays could not be routinely performed. Hence, it is necessary to investigate other biological markers such as metabolic markers. We aimed here to challenge the three main biological markers used for the diagnosis of nitrous oxide abuse as total vitamin B12, homocysteine, and methylmalonic acid. METHODS: We retrospectively collected clinical and biological data from 52 patients with known, documented chronic N2O abuse and associated clinical signs (peripheral neuropathy disability score or thrombosis event). Sera and plasma total vitamin B12, methylmalonic acid (MMA), and homocysteine were performed to identify the most specific marker of chronic N2O intoxication and related clinical outcomes. RESULTS: Plasma homocysteine was almost consistently increased in case of N2O chronic consumption, whereas MMA increase and total vitamin B12 decrease are not systematically found. Our results showed that none of the markers are correlated with levels of N2O consumptions. However, homocysteine and MMA are correlated with clinical severity, but MMA seems to be a better marker of clinical severity. CONCLUSION: There is no specific marker of nitrous oxide abuse according to levels of consumption, total vitamin B12 decrease could not be used either as consumption or as severity marker. However, we showed that homocysteine is consistently increased and could be used as marker of recent N2O consumption. On the other hand, we showed that MMA could be used as a marker of clinical gravity.

[Stratification of cardiovascular risk in women: Optimize the medical care]. / Stratification du risque cardiovasculaire de la femme : optimiser les prises en charge.

Cardiovascular diseases are become the primary cause of death in women. The cardiovascular risk of the woman has unknown specificities and remains underestimated. At equal age, women have more cardio vascular risk factors than men. All these specificities must be taken into account for an optimized evaluation of cardiovascular risk and for improvement of CV management in women. Some traditional risk factors are more deleterious in women such as hypertension, tobacco, diabetes or psycho-social stress and they are less well controlled compared to men. Women are also exposed to hormonal risk factors (contraception, pregnancy and menopause) or to emergent risk situations (migraine with aura, endometriosis, polycystic ovary syndrome, auto-immune diseases…). Conversely, lifestyle measures (regular physical activity, no smoking, healthy diet, stress management) are extremely effective in primary and secondary prevention in women. Predicting the risk of cardiovascular events in women is difficult because the classic risk scores (SCORE, Framingham…) do not take into account hormonal CV specificities and underestimate the women CV risk. Until then, only the specific women AHA stratification of CVR allowed for appropriate care for them. Recently, at the initiative of the French Society of hypertension, a consensus of experts proposed a stratification of CVR adapted to French women, to help practitioners in their care, especially for the two hormonal periods as contraception and menopause.

Association between reproductive factors and carotid atherosclerosis in post-menopausal women.

OBJECTIVES: Assessment of cardiovascular risk in women is specific and hormonal factors should be considered to avoid its underestimation. So far, studies on this issue are lacking and the impact of reproductive factors on cardiovascular risk has yet to be determined. We study the association between reproductive factors and carotid atherosclerosis, a non-invasive marker of cardiovascular diseases, in post-menopause. STUDY DESIGN: In this cross-sectional study, data were analyzed from post-menopausal women with at least one cardiovascular risk factor followed through a dedicated healthcare pathway at the Lille University Hospital between January 1st, 2013 and December 31st, 2016. MAIN OUTCOME AND MEASURES: The primary outcome was the presence of plaque or stenosis at carotid ultrasound. RESULTS: We included 370 post-menopausal women with a mean age of 63.4 ± 0.5 years. Carotid atherosclerosis was found in 161 (43,3%) women. Women with 3 or more children had higher odds of having carotid atherosclerosis than women with fewer than 3 children after adjustment for age, OR 1,69 [CI 95% 1,09-2,61], p = 0,019, and after further adjustment for anthropometric measures, traditional cardiovascular risk factors and pregnancy-related complications: OR 1,65 [CI 95% 1,05-2,62], p = 0,031. No other reproductive factor was significantly associated with carotid atherosclerosis. CONCLUSIONS: A higher parity was associated with higher odds of carotid atherosclerosis independently of age, traditional risk factors, anthropometric measures and gestational diseases among post-menopausal women at risk of cardiovascular diseases. This suggests the importance of considering the number of children when assessing cardiovascular risk in women.