Sleep-disordered breathing (SDB) and obstructive sleep apnea (OSA) in elderly population with high and low BMI

Background: SDB has a high prevalence in the elderly population.OSA has been recognized in 7-18% of elderly people. Aim: Evaluate clinical and sleep characteristics of OSA in a group of elderly patients with SDB according to BMI. Methods: 47 patients (34M,13F) over 70 yrs old with SDB divided in 2 groups according to BMI ( than 25.0). SDB are studied by means of cardiorespiratory polygraphy. Descriptive statistics were calculated for all variables. Statistical analyses were performed using S-Plus. Results: 19 patients with BMI 24.9 (group B). The group A (Mean age 75,6±4,2. BMI 23,6. SaO2 92,7±1,9%) reported more difficulty falling asleep (p<0.001) and more daytime sleepines (p=0.0014); AH index were 18,3±1,4 with prevalence of obstructive events as well as group B (AH index 17,6±1,5).Time in bed was 258,6±60,0 min and in group A. Group B (74,9±3,9 mean age. BMI 35,2±5. SaO2 90,7±5,0) had AH index and mean hypopnea duration (27,5±1,1 vs 38,6±4,2) lower than group A. Group B had no longer time in bed (286,2±76,2 min) than other group. Single regression analysis were performed by age related to time in bed, hypopnea duration and apnea duration and was statistically significant only in group A according to time to bed and age (p=.035). Conclusion: OSA in elderly patients is underdiagnosed. Atypical presentation in elderly patients are common. Low BMI in elderly not excluded OSA risk. We emphasized the need for adjusting the OSA criteria in elderly persons to avoid interpreting OSA symptoms attributable to other diseases more common in old patients.