Nocturnal physiological and biochemical changes in sudden unexplained death syndrome: a preliminary report of a case control study

Sudden nocturnal deaths among "healthy" workers in Southeast Asia have been termed "sudden unexplained nocturnal death syndrome (SUNDS)" or "sudden unexplained death syndrome (SUDS)". The pathogenesis is still unknown. The paucity of publications on nocturnal monitoring and scientific data stimulated us to perform this study, which included biochemical tests and physiological monitoring during the night in 11 males north-eastern Thai workers. Group 1 (G1) consisted of 5 subjects with neither a previous history of near-SUDS (NSUDS) nor a familial history of SUDS (FHSUDS). Group 2 (G2) consisted of 6 subjects with a family history of either SUDS or NSUDS. Two subjects in G2 presented with NSUDS. Two-day nocturnal monitoring included blood sugar, electrolytes, and respiratory parameters. 24-hour Holter ECGs were monitored for 2 days. The subjects underwent exercise stress tests on the 2nd day of this study. Significant nocturnal hypoxia was more common in G2 than G1 and this abnormality was aggravated by exercise. There were no significant findings in sleep apnea (apnea indices) or in nocturnal biochemical changes, eg blood sugar, electrolytes, thiamine. The recordings of the Holter-ECGs were within normal limits in both groups. We conclude that nocturnal hypoxia might be the primary abnormality in SUDS, and this abnormality was aggravated by the day-time exercise. The cause of nocturnal hypoxia requires further studies.

Efficacy and acceptability of perindopril in essential hypertension

The clinical efficacy and acceptability of once-daily perindopril (4 to 8 mg) monotherapy and in combination with hydrochlorothiazide (50 mg/day) was studied in mild to moderate stable essential hypertensive patients in 4 centres in Thailand. After 2-4 weeks of placebo run-in period, patients received active treatment for 3 months starting with 4 mg perindopril once daily. Dose titration was at second and third month of active treatment if the supine DBP was > 90 mmHg. The dose was doubled and if necessary, 50 mg/day hydrochlorothiazide was added in the last month. The results in 95 patients showed that the mean reduction in supine SBP/DBP at 1, 2 and 3 months of treatment was 10.3/8.0, 13.2/8.7 and 19.1/13.7 mmHg respectively. At the end of the study, 80 per cent of the patients showed normalisation of the supine diastolic blood pressure (supine DBP < or = 90 mmHg) with 30 per cent receiving combined therapy of perindopril and hydrochlorothiazide. There was no significant change in routine haematology or serum biochemistry except for slight increase of potassium levels in patients receiving 8 mg perindopril monotherapy. The incidence of side effects and withdrawal from treatment were quite low. Cough was the major side effect reported comprising 13.6 per cent with only 1 case withdrawn. The study confirms the previous studies that perindopril had satisfactory antihypertensive efficacy and acceptability profiles.