Impairment of baroreflex sensitivity by sequence technique in Frailty Syndrome

Frailty syndrome is characterized by progressive decline in the ability to maintain homeostasis as a result of declining resilience and physiological reserves. The evaluation of baroreflex could provide important information about this syndrome. The aim of this study was to evaluate the baroreflex in three groups: nonfrail, prefrail and frail. Twenty three older adults (61-89 years) were evaluated. The electrocardiographic signal (BioAmp FE132, ADInstruments, Australia) and the arterial blood pressure (Finometer Pro Finapres Medical Systems, Amsterdam, Netherlands) were recorded simultaneously for 15 minutes in supine and orthostatic position. The spontaneous baroreflex was evaluated by sequence technique (gain α_seq) in stationary sequences of 256 points. A two way ANOVA for repeated measures with Tukey post hoc was performed to evaluate the effects of group, position and interaction. A significance level was set to 5%. Nonfrail (n = 8; 67 ± 6 years), prefrail (n = 8; 72 ± 11 years) and frail (n = 7; 76 ± 9 years) showed no significant differences for age, gender and betablocker user. Only nonfrail group presented a significant reduction of gain α_seq in supine to orthostatic position (nonfrail: 8.15 ± 1.39 to 4.59 ± 1.86; prefrail: 6.97 ± 4.45 to 5.05 ± 1.90; frail: 5.48 ± 4.87 to 3.82 ± 2.71). These results suggest that frailty syndrome may be linked to an impairment of the baroreflex and could be already evident in the intermediate stage (prefrail). Funding: São Paulo Research Foundation (FAPESP) grant 2013/17936-9, grant 2012/04146-7 and 2010/52070-4; CAPES-PVE (process 23028.007721/2013-4) and CNPq (process 479769/2013-3).