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.
Kahleová
Regina
R
Institute of Inherited Metabolic Disease, Charles University, 1st Faculty of Medicine, Prague, Czech Republic.
Palyzová
Daniela
D
Zvára
Karel
K
Zvárová
Jana
J
Hrach
Karel
K
Nováková
Iva
I
Hyánek
Josef
J
Bendlová
Bela
B
Kozich
Viktor
V
D013766:5-Methyltetrahydrofolate-Homocysteine S-Methyltransferase / Q000235:genetics; D000293:Adolescent; D000328:Adult; D003541:Cystathionine beta-Synthase / Q000235:genetics; D005260:Female; D005287:Ferredoxin-NADP Reductase / Q000235:genetics; D005492:Folic Acid / Q000378:metabolism*; D020022:Genetic Predisposition to Disease / Q000453:epidemiology; D006710:Homocysteine / Q000378:metabolism*; D006801:Humans; D006973:Hypertension / Q000453:epidemiology / Q000235:genetics* / Q000378:metabolism*; D007333:Insulin Resistance; D008297:Male; D042965:Methylenetetrahydrofolate Reductase (NADPH2); D000587:Oxidoreductases Acting on CH-NH Group Donors / Q000235:genetics; D011110:Polymorphism, Genetic; D015995:Prevalence; D012307:Risk Factors; D014805:Vitamin B 12 / Q000378:metabolism; D025101:Vitamin B 6 / Q000378:metabolism
D006710:Homocysteine; D025101:Vitamin B 6; D005492:Folic Acid; C111241:methionine synthase reductase; D005287:Ferredoxin-NADP Reductase; D000587:Oxidoreductases Acting on CH-NH Group Donors; D042965:Methylenetetrahydrofolate Reductase (NADPH2); D013766:5-Methyltetrahydrofolate-Homocysteine S-Methyltransferase; D003541:Cystathionine beta-Synthase; D014805:Vitamin B 12