Interventions aimed to increase average 24-h systolic blood pressure reduce blood pressure drops in patients with reflex syncope and orthostatic intolerance.

AIMS: Systolic blood pressure (SBP) drops recorded by 24-h ambulatory blood pressure (BP) monitoring (ABPM) identify patients with susceptibility to reflex syncope and orthostatic intolerance. We tested the hypothesis that treatments aimed to increase BP (reassurance, education, and lifestyle measures plus pharmacological strategies) can reduce SBP drops. METHODS AND RESULTS: This was a multicentre, observational proof-of-concept study performed in patients with reflex syncope and/or orthostatic intolerance and with SBP drops on a screening ABPM. Among 144 eligible patients, 111 underwent a second ABPM on average 2.5 months after start of treatment. Overall, mean 24-h SBP increased from 114.1 ± 12.1 to 121.4 ± 14.5 mmHg (P < 0.0001). The number of SBP drops <90 and <100 mmHg decreased by 61%, 46% during daytime, and by 48% and 37% during 24-h period, respectively (P < 0.0001 for all). The dose-response relationship between difference in 24-h average SBP increase and reduction in number of SBP drops reached a plateau around ∼15 mmHg increase of 24-h SBP. The reduction in SBP drop rate was consistent and significant in patients who underwent deprescription of hypotensive medications (n = 44) and in patients who received BP-rising drugs (n = 67). CONCLUSION: In patients with reflex syncope and/or orthostatic intolerance, an increase in average 24-h SBP, regardless of the implemented strategy, significantly reduced the number of SBP drops and symptom burden. A 13 mmHg increase in 24-h SBP appears to represent the optimal goal for aborting the maximal number of SBP drops, representing a possible target for future interventions. ClincalTrials.gov identifier: NCT05729724.

Reference intervals for free T3 and free T4 in Pakistani euthyroid patients: effect of age and gender on thyroid function.

OBJECTIVE: To establish reference intervals for Free Triiodothyronine (FT3) and Free Thyroxine (FT4) in euthyroid subjects and to assess the effect of age and gender on FT3 and FT4. STUDY DESIGN: Cross-sectional, analytical study. PLACE AND DURATION OF STUDY: Institute of Nuclear Medicine and Oncology (INMOL), Lahore, from January 2009 to April 2011. METHODOLOGY: FT3 and FT4 were measured in 852 euthyroid patients. Those with previous thyroid surgery, on thyroidrelated medication and severe non-thyroid illness were excluded. RESULTS: There were 215 males and 637 females with mean age of 46 years. The reference intervals, revealed by this study, for FT3 and FT4 were 2.80 - 5.39 pmol/L and 11.9 - 22.2 pmol/L respectively. The mean difference between gender groups and age groups was found statistically significant for FT3 (gender: p < 0.001; age: p < 0.001) but statistically insignificant for FT4 (gender: p=0.147; age: p=0.201). CONCLUSION: There was no effect of gender and age on FT3 and FT4. The age with serum FT3 and FT4 significantly negatively correlated but this correlation was stronger for FT3 as compared to FT4 levels. Reference intervals of FT3 and FT4 for male (2.99 - 5.63 pmol/L, 12.3 - 22.6 pmol/L) and female (2.77 - 5.29 pmol/L, 11.7 - 22.1 pmol/L) respectively are suggested.