Essential hypertension in adolescents:: Association with insulin resistance and with metabolism of homocysteine and vitamins

Background: Although insulin resistance and elevated plasma homocysteine are associated with hypertension in adults, the role of these conditions in the initial phase of hypertension is largely unknown. We examined whether insulin resistance and disturbed homocysteine metabolism are present in young adults at the early stages of essential hypertension. Methods: We measured physical characteristics, plasma levels of insulin, lipids, total homocysteine, and vitamins in 164 patients with essential juvenile hypertension (median age, 19 years; 92% males) and in 173 controls (median age, 18 years; 66% males). Furthermore, we analyzed the prevalence of six polymorphisms in four genes of the methionine cycle. Results: Patients with hypertension and controls differed significantly (P < .05) in body mass index, levels of insulin, high-density lipoprotein-cholesterol, fasting and post-load plasma homocysteine, and folates. Systolic blood pressure was correlated with homocysteine levels and inversely correlated with plasma folates. Logistic regression showed that fasting homocysteine, vitamin B-12, and low-density lipoprotein-cholesterol were associated with a significantly increased risk of juvenile hypertension. In contrast, the birth length, polymorphism c.2756 A --> G in the MTR gene and plasma folate were associated with a significantly decreased risk of juvenile hypertension. Conclusions: Our study showed that essential hypertension in adolescents is associated with lower folate and higher homocysteine levels, and with signs of insulin resistance. These data suggest that hypertension in young individuals may be a part of early manifestation of insulin resistance syndrome, and that disturbed folate and homocysteine metabolism may play a role in the early stages of hypertension. (C) 2002 American Journal of Hypertension, Ltd.