Sir,—It is known that transient elevations in blood pressure are not solely attributable to internal factors; the person who takes the blood pressure measurement may also induce an increase in blood pressure.1 An example of this phenomenon is white coat hypertension.2 The present study compared the difference between blood pressure readings in male Japanese adolescents when measured by men and women.

We studied 373 consecutive male college freshmen (aged 18–20 years) during an annual check up programme. None of them had any evidence of clinically significant disease such as hypertension (⩾ 140 mm Hg), heart valve disease, arrhythmia, hypercholesterolaemia, renal impairment, or liver disease. In March 1997, blood pressures and pulse rates of these subjects were measured using a semiautomatic sphygmomanometer …