Blood pressure increases during acute exposure to high altitude in healthy humans. However, little is known on altitude effects in hypertensive subjects or on the treatment efficacy in this condition. Objectives of High Altitude Cardiovascular Research (HIGHCARE)–Andes Lowlanders Study were to investigate the effects of acute high-altitude exposure on 24-hour ambulatory blood pressure in hypertensive subjects and to assess antihypertensive treatment efficacy in this setting. One hundred untreated subjects with mild hypertension (screening blood pressure, 144.1±9.8 mm Hg systolic, 92.0±7.5 mm Hg diastolic) were randomized to double-blind placebo or to telmisartan 80 mg+modified release nifedipine 30 mg combination. Twenty-four–hour ambulatory blood pressure monitoring was performed off-treatment, after 6 weeks of treatment at sea level, on treatment during acute exposure to high altitude (3260 m) and immediately after return to sea level. Eighty-nine patients completed the study (age, 56.4±17.6 years; 52 men/37 women; body mass index, 28.2±3.5 kg/m ² ). Twenty-four–hour systolic blood pressure increased at high altitude in both groups (placebo, 11.0±9 mm Hg; P <0.001 and active treatment, 8.1±10.4 mm Hg; P <0.001). Active treatment reduced 24-hour systolic blood pressure both at sea level and at high altitude (147.9±11.1 versus 132.6±12.4 mm Hg for placebo versus treated; P <0.001; 95% confidence interval of the difference 10.9–19.9 mm Hg) and was well tolerated. Similar results were obtained for diastolic, for daytime blood pressure, and for nighttime blood pressure. Treatment was well tolerated in all conditions. Our study demonstrates that (1) 24-hour blood pressure increases significantly during acute high-altitude exposure in hypertensive subjects and (2) treatment with angiotensin receptor blocker-calcium channel blocker combination is effective and safe in this condition. Clinical Trial Registration—: URL: http://www.clinicaltrials.gov . Unique identifier: NCT01830530.

During the COVID-19 pandemic, the use of protective masks has been essential to reduce contagions. However, public opinion is that there is an associated subjective shortness of breath. We evaluated cardiorespiratory parameters at rest and during maximal exertion to highlight any differences with the use of protective masks.12 healthy subjects performed three identical cardiopulmonary exercise tests, one without wearing a protective mask, one wearing a surgical mask and one with a filtering face piece particles class 2 (FFP2) mask. Dyspnoea was assessed using the Borg scale. Standard pulmonary function tests were also performed.All the subjects (40.8±12.4 years; six male) completed the protocol with no adverse events. Spirometry showed a progressive reduction of forced expiratory volume in 1 s (FEV₁) and forced vital capacity (FVC) from no mask to surgical to FFP2 (FEV₁: 3.94±0.91 L, 3.23±0.81 L, 2.94±0.98 L; FVC: 4.70±1.21 L, 3.77±1.02 L, 3.52±1.21 L; p<0.001). Rest ventilation, O₂uptake (V˙O₂) and CO₂production (V˙CO₂) were progressively lower, with a reduction in respiratory rate. At peak exercise, subjects had a progressively higher Borg scale when wearing surgical and FFP2 masks. Accordingly, at peak exercise,V˙O₂(31.0±23.4 mL·kg⁻¹·min⁻¹, 27.5±6.9 mL·kg⁻¹·min⁻¹, 28.2±8.8 mL·kg⁻¹·min⁻¹; p=0.001), ventilation (92±26 L, 76±22 L, 72±21 L; p=0.003), respiratory rate (42±8 breaths·min⁻¹, 38±5 breaths·min⁻¹, 37±4 breaths·min⁻¹; p=0.04) and tidal volume (2.28±0.72 L, 2.05±0.60 L, 1.96±0.65 L; p=0.001) were gradually lower. There was no significant difference in oxygen saturation.Protective masks are associated with significant but modest worsening of spirometry and cardiorespiratory parameters at rest and peak exercise. The effect is driven by a ventilation reduction due to increased airflow resistance. However, because exercise ventilatory limitation is far from being reached, their use is safe even during maximal exercise, with a slight reduction in performance.

Pendred syndrome (PS) is the most frequent form of genetically related syndromic hearing loss, and is associated with mutations of pendrin, encoded by the SLC26A4 gene. This protein localizes to the cellular membrane and permits the exchange of anions between the cytosol and extracellular space. In the inner ear, pendrin conditions the endolymph, allowing for the proper function of sensory cells. Understanding the relationship between the genotype and phenotype of pendrin mutations would aid clinicians to better serve PS patients–however, little is known. Here, we summarize the available data concerning SLC26A4 mutations and how they relate to transporter function. The main findings suggest that all the truncation mutations tested annihilate pendrin function, and that the addition or omission of proline, or the addition or omission of charged amino acids in the sequence of SLC26A4 result in a substantial to dramatic reduction in pendrin function.