This study followed a small number of men previously studied polysomnographically 10 yr earlier to investigate the relationship between the development of sleep-disordered breathing and age, weight gain, and smoking. In 1984, 3,201 men answered a questionnaire including questions about snoring and excessive daytime sleepiness (EDS). Of those reporting symptoms related to obstructive sleep apnea syndrome (OSAS), a random sample of 61 men was investigated using whole-night polysomnography in 1985. Ten years later, 38 men participated in the present follow-up, which included a structured interview and polysomnography. During the 10-yr period, nine men had been treated for OSAS. Of the 29 untreated subjects, the number of men with OSAS, defined as an apnea-hypopnea index (AHI) of >/= 5/h, increased from four in 1985 to 13 in 1995 (p < 0.01). In this small sample, no significant associations were found between DeltaAHI (i.e., AHI 1995 - AHI 1985) and age, weight gain, or smoking. We conclude that, among this small group of individuals who were selected for original polysomnographic study and follow-up because they were thought to have symptoms of sleep apnea, sleep-disordered breathing became significantly worse over time.