Table 1.
Epidemiology of SUNDS in Different Countries
| Country | Ethnicity | Inclusion Criteria | SUNDS Cases | Inci.a | Mean Age | Peak Risk Age (y) | Sex Ratiob | Peak Risk Month | Occupation | Symptoms Before Death | Ref |
|---|---|---|---|---|---|---|---|---|---|---|---|
| USA (1981)c | South‐East Asian refugees in the USA |
25–63 y old SCD at night or during sleep postmortem autopsy Negatived |
25 | 59–92 | 33 | NA | NA | NA | NA | Choking, gurgling, gasping, or labored respirations, without wheezing or stridor | 5, 8 |
| USA (1987) | 5 | 1 | 33 | NA | 5/0 | NA | NA | NA | 8 | ||
| Singapore (1982–1990) | Thai workers in Singapore |
21–54 y old SCD during sleep Postmortem autopsy (57/161 done) negative |
161 | 78 | 34 | NA | 161/0 | No mo pattern | Construction worker | Noisy breathing, gasping, or groaning | 9 |
| Thailand (1990) | Thai‐Lao in the northeast |
20–49 y old SCD during night or daytime sleep Seemed to be healthy (Postmortem autopsies were not done in all cases) |
31 | 38 | 38 | 45–49 | 30/1 | Apr | Farmer or laborer | Groaning, muttering, choking or coughing, nightmare or night terror, restless sleep, spastic rigidity with or without contracting limbs, board‐like rigidity of abdominal wall, salivation, tongue biting | 10 |
| Philippines (1948–1982) | Filipinos in Manila |
25–44 y old SCD during sleep or nap Postmortem autopsy (95% done) negative |
772 | 10.8–26.3 | 33 | 30–34 | 24/1 | Dec–Jan | NA | NA | 11 |
| Philippines (2003) | Filipinos |
20–39 y old No postmortem autopsy |
8 | 43 | 29.75 | NA | 3/1 | NA | NA | No moaning | 12 |
| China (2001–2013) | Han population of China |
15–55 y old SCD during nocturnal sleep Postmortem autopsy negative |
1854 | 1 | 32 | 30 | 13.8/1 | Apr–Jun | Blue‐collar worker (97.7%) | Sudden tachypnea, strange groan or gasping, scream, abnormal snoring, sudden cough, abrupt tic of limbs, abrupt discomfort, white froth through mouth, feeling cold before retiring | 3, 13 |
NA indicates not available; Ref, references; SCD, sudden cardiac death; SUNDS, sudden unexplained nocturnal death syndrome.
a
Inci: incidence: 1/100 000.
b
Sex ratio: male/female.
c
The year SUNDS cases were collected from.
d
Postmortem autopsies were negative: no lethal acute coronary thrombosis, myocardial infarction, or myocarditis accounting for death.