L-Arginine and Nitric Oxide Level amongPregnant Women in Sokoto, Nigeria

Pregnancy is a state of relative arginine deficiency imposed by the increased formation of nitric oxide to support the adaptive vasodilatation of pregnancy. This case control study involved a total of 74 pregnant (subjects) and 50 non-pregnant women (controls). The subjects were aged 19 years to 40 years with mean age of 27.6±5.0 years. The mean values of L-arginine level among 74 pregnant subjects was (173±63.7μmol/L) compared to (137.9±89.5μmol/L) among 50 non-pregnant control group is (p=0.271). The mean values of Nitric Oxide level among the pregnant subjects (334±80.6μmol/L) was significantly higher that that among the non-pregnant controls (280.5±130μmol/L) (p=0.002). The mean values of L-arginine and nitric oxide were compared among the subjects based on trimester. There was no significance difference in the L-arginine and nitric oxide levels (175±63.9) and (303.5±118) among pregnant women within their first trimester and second trimester (185.5±61) and (344±74) (p=0.337 and 0.750) respectively. There was no significance difference in the mean values of L-arginine and nitric Oxide among pregnant women in the second (185.5±61) and (344±74) and third trimester of pregnancy (161±65.5) and (328±83) (p=0.115 and 0.409) respectively. Similarly, there was no significance difference in the mean values of Larginine and nitric Oxide among pregnant women in the first (175±63.9) and (303.5±118) and third semester (161±65.5) and (328±83) (p=0.704 and 0.407). The mean value of L-arginine and nitric oxide was compared based on ethnicity of the subjects. L-arginine and nitric oxide levels among Hausa/Fulani ethnic group is (167.8±63) and (330.7±75) respectively. The mean value of L-arginine and nitric oxide level among Yoruba ethnic group is (168.5.5±76) and (411±57) respectively. While the mean values of L-arginine and nitric oxide among Igbo ethnic group is (217±57) and (237.8±128) respectively. There were no significant differences in the L-arginine levels among subjects based on ethnicity (p>0.05). The nitric oxide level was significantly higher among Hausa/Fulani (330.7±75) compared to the Igbo ethnic group (237.8±124) (p=0.046). The mean values of L-arginine and nitric oxide was compared based on parity. The mean values of L-arginine and nitric oxide among pregnant women who are carrying their first pregnancy is (148±55.7) and (348.8±75.5) respectively. The mean values of L-arginine and nitric oxide among para 1,2,3,4, and >4 pregnant women were; (190.9±72.9) and (318.7±56), (151±56.8) and (341.6±81.7), (201±48) and (306±91.8), (146±67) and (346±57.8) and (181±70) and (348±98.8) respectively. There was a statistically significant difference in the mean L-arginine levels between para 2 (151±56.8) and 3 women (201±48) (p=0.029). Similarly, the mean L-arginine levels was significantly higher among para 3 (201±48) compared to para 0 pregnant women (148±55.7) (p=0.010). There were no statistically significant differences in the mean L-arginine and nitric oxide based on the on the occupation of husband and the level of educational attainment of the subjects (p>0.05). In conclusion, finding from this study confirmed that the level of L-arginine and nitric oxide is higher among pregnant subjects compared to non-pregnant controls. Gestational age (trimester), ethnicity, parity, and socio-economic status was also found to have effect on the level of L-arginine and nitric oxide. We recommend that further research need to be conducted involving a larger population of pregnant women with different gestational age, parity, ethnicity and socio-economic status.We also recommend that pregnant women found to have low level of L-arginine and nitric oxide should be given L-arginine supplements as a prophylaxis. We recommend that public enlightenment programme should be implemented to enlighten pregnant women on how to maintain the normal level of L-arginine and nitric oxide through taking a balance diet and food that serve as a source of L-arginine. We also recommend that pregnant women should be offered a routine L-arginine and nitric oxide test to monitor their level of L-arginine and nitric oxide.