Blood pressure responses are dependent on call type and related to hypertension status in firefighters

BACKGROUND

Impaired cardiovascular health is a concern for firefighters, with over 50% of line-of-duty deaths having cardiac causes. Many firefighters have hypertension and <25% have their blood pressure (BP) controlled. The alarm response could be an unidentified cardiac risk, but interestingly, the BP response to different calls and on-the-job activity is unknown.

PURPOSE

We aimed to measure the physiological stress resulting from different call types (fire, medical) and job activity (riding apparatus, pre-alert alarms) through ambulatory BP (ABP) monitoring in a population of firefighters.

MATERIALS AND METHODS

During 111 12-h work shifts firefighters wore an ABP monitor. BP was measured at 30-min intervals and manual measurements were prompted when the pager went off or whenever they felt stress.

RESULTS

Firefighters were hypertensive (124.3 ± 9.9/78.1 ± 6.7 mmHg), overweight (30.2 ± 4.6 kg/m2), middle-aged (40.5 ± 12.6 years) and experienced (17.3 ± 11.7 years). We calculated an average 11% increase in systolic and 10.5% increase in diastolic BP with alarm. Systolic BP (141.9 ± 13.2 mmHg) and diastolic BP (84.9 ± 11.1 mmHg) and the BP surges were higher while firefighters were responding to medical calls compared to fire calls. Between BP groups we found that medical call systolic BP (p = .001, d = 1.2), diastolic BP (p = .017, d = 0.87), and fire call systolic BP (p = .03, d = 0.51) levels were higher in the hypertensive firefighters.

CONCLUSION

This is the first report of BP surge responses to alarms and to occupational activities in firefighters, and medical calls elicited the largest overall responses.PLAIN LANGUAGE SUMMARYCardiovascular disease and impaired cardiovascular health are substantially more prevalent in firefighters, with over 50% of line-of-duty deaths being cardiac related.Many firefighters are diagnosed with high blood pressure (hypertension), which is known to increase the risk of heart attacks, strokes, heart disease, and other serious health complications.Upon stress, our body enacts the 'fight or flight' response where sympathetic nervous system activity triggers an immediate increase in heart rate and blood pressure. This response can be dangerous when surges reach extreme levels due to underlying impaired cardiovascular function. It is known that alarm sounds trigger a stress response.Firefighters respond to different alarms while on the job, each indicating different call types, such as a house fire or a medical emergency. Due to the prevalence of impaired cardiovascular health in firefighters, the physical stress resulting from these alerts is cause for concern.The blood pressure surge response to different call types and job activities in healthy and hypertensive firefighters had not been measured before this study.Through the ambulatory blood pressure monitoring of 111 on-duty firefighters, this study discovered that medical calls caused the greatest blood pressure and heart rate surge.Also, firefighters with hypertension experienced a greater blood pressure surge in response to alarms than their non-hypertensive co-workers.

A novel morpholino oligomer targeting ISS-N1 improves rescue of severe spinal muscular atrophy transgenic mice

In the search for the most efficacious antisense oligonucleotides (AOs) aimed at inducing SMN2 exon 7 inclusion, we systematically assessed three AOs, PMO25 (-10, -34), PMO18 (-10, -27), and PMO20 (-10, -29), complementary to the SMN2 intron 7 splicing silencer (ISS-N1). PMO25 was the most efficacious in augmenting exon 7 inclusion in vitro in spinal muscular atrophy (SMA) patient fibroblasts and in vitro splicing assays. PMO25 and PMO18 were compared further in a mouse model of severe SMA. After a single intracerebroventricular (ICV) injection in neonatal mice, PMO25 increased the life span of severe SMA mice up to 30-fold, with average survival greater by 3-fold compared with PMO18 at a dose of 20 μg/g and 2-fold at 40 μg/g. Exon 7 inclusion was increased in the CNS but not in peripheral tissues. Systemic delivery of PMO25 at birth achieved a similar outcome and produced increased exon 7 inclusion both in the CNS and peripherally. Systemic administration of a 10-μg/g concentration of PMO25 conjugated to an octaguanidine dendrimer (VMO25) increased the life span only 2-fold in neonatal type I SMA mice, although it prevented tail necrosis in mild SMA mice. Higher doses and ICV injection of VMO25 were associated with toxicity. We conclude that (1) the 25-mer AO is more efficient than the 18-mer and 20-mer in modifying SMN2 splicing in vitro; (2) it is more efficient in prolonging survival in SMA mice; and (3) naked Morpholino oligomers are more efficient and safer than the Vivo-Morpholino and have potential for future SMA clinical applications.