Raised plasma catecholamines in old and young patients with disproportionate systolic hypertension

Sympathetic nerve tonicity was assessed in hypertensives with either proportionate or disproportionate elevation of systolic blood pressure: patients were segregated into two groups, age less than 40 years and age 40 years and greater. Plasma catecholamines of sixty patients with proportionate hypertension and thirty five with disproportionate hypertension were compared with those of sixty one age matched normotensive volunteers. Disproportionate patients were younger than proportionate hypertensives in the age group less than 40 years (p less than .01) and were older than proportionate in the 40 years and older group (p less than .01). The youngest and oldest patients with disproportionate systolic hypertension tended to have normal diastolic blood pressure. Total plasma catecholamines were increased in both groups of hypertensives, whether young or old. However, only values in male hypertensives were increased significantly when compared with normotensives (p less than .01). Enhanced sympathetic nervous system tonicity appears to be an important factor in the cause and maintenance of both proportionate and disproportionate systolic hypertension.