Long-term trends of asthma, allergic rhinitis and atopic eczema in young Finnish men: a retrospective analysis, 1926-2017.

The aim of this study was to assess the long-term time trends of the prevalence of asthma, allergic rhinitis and atopic eczema in young Finnish men.A retrospective analysis was carried out on cross-sectional data from the Finnish Defence Forces taken from call-up examinations of candidates for military conscription and examinations of conscripts discharged from service because of poor health. Roughly 1.7 million men aged 18‒19 years (98% of men of conscription age) were examined from 1966 to 2017. A proportional but unknown number of young men were examined from 1926 to 1961.The main outcome measures were asthma recorded at call-up examination as the main diagnosis in 1926‒2017 and any diagnosis in 1997‒2017, exemption or discharge from military service due to asthma, and allergic rhinitis and atopic eczema recorded as the main diagnosis in 1966‒2017 and any diagnosis in 1997‒2017.During 1926-1961 the prevalence of asthma remained low at between 0.02% and 0.08%. A linear rise began between 1961 and 1966, with a 12-fold increase in the prevalence from 0.29% in 1966 to 3.44% in 2001. Thereafter, the prevalence of asthma as the main diagnosis stabilised but continued to increase to 5.19% in 2017 if secondary diagnoses of asthma were included. Exemption rates from military service due to asthma have similarly increased but fluctuated more. The prevalence of allergic rhinitis increased from 0.06% to 10.70% and atopic eczema from 0.15% to 2.90% during the period 1966‒2017.In Finland, an increase in asthma and allergic conditions among young men became evident in the mid-1960s. The increase slowed in the 2000s and may be levelling off in the 2020s.

Alarming development of dual snus and cigarette usage among young Finnish males.

BACKGROUND: The consumption of tobacco products has evolved to include more complex combinations of different products. We investigated the tobacco habits of a representative population of young Finnish male conscripts in order to evaluate the prevalence of dual use of cigarettes and snus as well as the transition from one tobacco product to another. In addition, we evaluated the correlation between the level of education and the use of cigarettes and snus. METHODS: A questionnaire-based survey was carried out in three out of 17 garrisons among conscripts during their first week of service in 2014. A total of 1971 male conscripts were selected by simple random sampling of the 9013 males in the selected garrisons. Of them 1916 participated and filled in the questionnaire. The response rate was 97.2%. The questionnaire consisted of 25 questions including age, gender, basic education, use of tobacco products as well as questions assessing nicotine dependency. RESULTS: The amount of dual users of cigarettes and snus was 21%. There was a higher probability of dual use of cigarettes and snus among smokers compared to snus users (p < 0.001). One third (35%) of former smokers reported daily snus use and over 40% of the former snus users smoked daily. One third (34%) of the participants reported snus usage and 14% of the study subjects used snus daily. 40% of the study population were smokers and over 25% smoked daily. Of the participants with basic educational background 57% smoked daily (p < 0.001), however, no association between snus and level of education was found (p = 0.69). CONCLUSIONS: This study provides better understanding of the complex tobacco habits of young adult males. The simultaneous usage of multiple tobacco products as well as the high tendency to transition from one tobacco product to another should be taken into consideration when planning cessation interventions in health care settings and tobacco control policies at societal levels.

Factors predicting willingness to quit snus and cigarette use among young males.

The health hazards of smoking are well recognised and recently knowledge about the harmful effects of nicotine and snus is accumulating. We investigated the factors increasing the willingness of young Finnish males to quit snus and cigarette smoking. We conducted a questionnaire study conducted in 3 out of 16 Finnish Defence Forces units which included 6508 male conscripts, of whom 4706 responded (response rate 72%, mean age 19.4 years). Factors related to the willingness to quit use were analysed by ordinal regression models. Backward selection following the Akaike information criterion (AIC) was used for the model. The prevalence figures of daily snus use and smoking were 17% and 25%, respectively. 16% of the daily snus users were also daily smokers and 29% were occasional smokers. Multivariate analysis showed that the willingness to quit snus use was associated with the perception of health hazards (OR 3.09, 95% CI 1.94-4.93) and with ≥ 2 quit attempts (OR 3.63, 95% CI 2.44-5.40). The willingness to quit smoking was associated with ≥ 2 quit attempts (OR 3.22, 95% CI 2.32-4.49), and with advice to quit smoking (OR 1.65, 95% CI 1.17-2.32). We created a brief two-question assessment model for snus dependence. With this model, nicotine dependence of daily snus users was congruent with that of nicotine dependence of smokers. A direct comparison with serum cotinine levels is necessary before our assessment model can be used as a proxy for dependence. Regular snus use predisposes to nicotine addiction and accumulated health hazards. Our findings underscore the importance of health promotion efforts in early adolescence and of active support for quitting snus use. Easily applicable tools to estimate nicotine addiction are needed for everyday clinical use.

Unaltered blood coagulation and platelet function in healthy subjects exposed to acute hypoxia.

INTRODUCTION: Acute hypoxia has been suspected to cause blood coagulation and platelet activation. Our aim was to study blood coagulation and platelet function during a short hypoxic exposure. METHODS: Healthy nonsmoking men (N = 10) inhaled a normobaric hypoxic gas mixture containing 8% of oxygen (92% nitrogen) for 7 min via a face mask. Venous blood was collected 5 min before and during the 5 to 7 min of hypoxia exposure (i.e., pretest and hypoxia samples, respectively) while monitoring arterial oxygen saturation (SaO2) with pulse oximetry. Blood sampling was completed in 2 min and the face mask was removed. Venous epinephrine and norepinephrine, complete blood counts, and a panel of coagulation markers were analyzed. Platelet aggregation induced by ristocetin, adenosine diphosphate (ADP), arachidonic acid, and thrombin receptor activating peptide was studied with Multiplate and shear force-dependent functions with PFA-100R (collagen/epinephrine and collagen/ADP cartridges), both assays in whole blood. RESULTS: During hypoxia, SaO2 declined from 98 to 58% (ranges 97-99% vs. 42-85%), while heart rate increased from 69/min to 94/min (SD 11 vs. SD 13). Venous epinephrine and norepinephrine levels also increased. This short hypoxia induced minor but uniform increases in red cells, reticulocytes, and leukocytes and decreases in platelet counts. Plateletfunctions and prothrombin time, APTT, thrombin time, D-dimer, fibrinogen levels or von Willebrand factor (VWF), antithrombin, factor V (FV) or FVIII activities did not change. DISCUSSION: Profound acute hypoxia failed to affect blood coagulation or platelet functions in healthy individuals.

Prevalence, duration of exposure and predicting factors for snus use among young Finnish men: a cross-sectional study.

OBJECTIVE: The health hazards of tobacco products depend on the level of exposure, but little is known about the characteristics of snus use. The aim of this study was to investigate the duration of daily exposure to snus among occasional and daily users and its associated predictive factors among young Finnish men. DESIGN: Cross-sectional questionnaire study. SETTING: Three out of 16 Finnish Defence Forces units. PARTICIPANTS: 1280 young Finnish male conscripts starting their military service in 2016 chosen by simple random sampling. PRIMARY AND SECONDARY MEASURES: The prevalence, duration of use and the amount of daily usage of snus and cigarettes were investigated. The attitudes towards perceived harmfulness of snus and the predictive factors affecting the total time of snus consumption were examined. RESULTS: Almost a fifth (19.5%) of the conscripts reported daily snus use, and a further 16% reported occasional use. Daily snus use was associated with an earlier starting age, longer duration of use and higher daily exposure time compared with occasional use. On average, daily snus users consumed 10 portions and occasional users three portions per day (p<0.001). The daily total exposure time for daily users was 372 min (95% CI 344 to 401) and for occasional users 139 min (95% CI 106 to 171). Respondents with an upper secondary education had significantly less daily total exposure than those with basic comprehensive education (p=0.036). Perceptions of snus as a harmful substance resulted in a significantly lower duration of exposure. CONCLUSION: Snus use was very common among young Finnish men. High snus exposure duration was associated with an earlier starting age, a longer history of use and a careless attitude to its health hazards. A higher education level was a protective factor for total exposure time. Studies of the long-term health effects and dependency profile of snus use are needed.

Neck and back muscle loading in pilots flying high G(z) sorties with and without lumbar support.

INTRODUCTION: Fighter pilots frequently encounter neck and back pain and injuries due to high G(z) loading. A lumbar support could diminish muscle strain in the lower back under G(z) loading and might also have a positive effect on cervical muscle strain, due to a more ergonomic sitting posture. The aim of this study was to determine the effects of individually adjusted lumbar supports on fighter pilots' neck and back muscle loadings. METHODS: There were 11 Finnish Air Force pilots who acted as test subjects. They flew two basic air combat maneuvering sorties with and without the LS. The EMG activity of the sternocleidomastoid (SCM), cervical (CES), thoracic (TES), and lumbar erector spinae muscles (LES) were measured during these sorties, and the number and duration of EMG gaps was analyzed. Subjective experiences about the lumbar support were evaluated using a questionnaire. RESULTS: In all measured muscles, mean percent maximal voluntary contraction (%MVC) was lower when the LS was used, yet these changes were not statistically significant. Individual differences in %MVC between flights diminished in the CES (9%), TES (7%), and LES (8%) with LS in use. There was also a tendency toward increased number of gaps in EMG activity when flying with the LS. According to questionnaire responses, the LS seems to relieve in-flight symptoms and reduce the fatigue in the lower back muscles. Not all subjects benefited from the LS, however. CONCLUSION: There seems to be a tendency toward a lower muscle strain with the LS, but there are considerable individual differences.

Neck muscle strain when wearing helmet and NVG during acceleration on a trampoline.

INTRODUCTION: The helmet-mounted equipment worn by military pilots increases the weight of the helmet system and shifts its center of gravity, increasing the loads on neck structures, especially during acceleration. The aim of this study was to determine neck muscle strain with different head-loads during trampoline-induced G loads (0 to +4 G). METHODS: Under three conditions [no helmet, helmet, helmet with night vision goggles (NVG)], 14 subjects performed trampoline exercises including basic, hand-and-knee, and back bouncing. EMG activity was measured for the sternocleidomastoid (SCM), cervical erector spinae (CES), trapezoid (TRA), and thoracic erector spinae (TES) muscles. Muscle strain was determined as a percentage of maximal voluntary contraction (%MVC). RESULTS: For the three exercises combined, the following significant changes were found: compared to control, the helmet increased muscle strain by 18%, 28%, and 18% in the SCM, CES, and TRA, respectively; NVG produced a further increase of 11% in the SCM and 6% in the CES. During back bouncing, the helmet increased muscle strain by 14% in the SCM and 19% in the CES, and NVG further increased this strain by 14% in the SCM. Hand-and-knee bouncing loaded extensors: the helmet caused increases of 46% in the CES and 29% in the TES, while NVG produced a further 13% increase in CES activation. CONCLUSION: Helmet weight alone had a large effect on muscular workload. The additional frontal weight of the NVG caused a further increase in the activity of cervical muscles that were already subjected to high strain.

Ambient temperature and neck EMG with +Gz loading on a trampoline.

INTRODUCTION: Fighter pilots who are frequently exposed to severe cold ambient temperatures experience neck pain disabilities and occupational disorders more often than those who are not so exposed. We hypothesized that a cold-induced increase in muscle strain might lead to in-flight neck injuries. The aims of this study were to measure the level of cooling before takeoff and to determine muscle strain under Gz loading (0 to +4 Gz) at different temperatures. METHODS: Test subjects' (n = 14) skin temperature (T(skin)) over the trapezoids was measured before the walk to the aircraft and again in the cockpit (air temperature -14 degrees C). The subjects then performed trampoline exercises in two different ambient temperatures (-2 degrees C and +21 degrees C) after a 30-min period at the respective temperatures. EMG activity of the sternocleidomastoid (SCM), cervical erector spinae (CES), trapezoid (TRA), thoracic erector spinae (TES) muscles, and Tskin of the SCM and TRA were measured. RESULTS: Tskin over the trapezoids decreased from 30.1 +/- 1.7 degrees C to 27.8 +/- 2.6 degrees C (p < 0.001) before takeoff. The change of muscle strain in cold was +11.0% in SCM, +14.9% in CES, +3.7% in TRA, and -1.7% in TES. Change was statistically significant in the cervical, uncovered area (SCM, CES). The linear regression model indicated a 2.6% increase in muscle strain per every decreased degree centigrade in skin temperature over the SCM. CONCLUSION: Superficial cooling over the neck muscles was significant prior to takeoff. Muscle loading in the cold caused higher EMG activity. A major increase in muscle strain was seen in the cervical muscles. These findings suggest a cold-induced increase in muscle strain during in-flight Gz loading.

Trampoline exercise vs. strength training to reduce neck strain in fighter pilots.

INTRODUCTION: Fighter pilots' muscular strength and endurance are subjected to very high demands. Pilots' fatigued muscles are at higher risk for injuries. The purpose of this study was to compare the effects of two different training methods in reducing muscular loading during in-flight and cervical loading testing (CLT). METHODS: There were 16 volunteer Finnish Air Force cadets who were divided into 2 groups: a strength training group (STG) and a trampoline training group (TTG). During the 6-wk training period, the STG performed dynamic flexion and extension and isometric rotation exercises, and the TTG performed trampoline bouncing exercises. During in-flight and CLT, muscle strain from the sternocleidomastoid, cervical erector spinae, trapezius, and thoracic erector spinae muscles was recorded with EMG. RESULTS: In-flight muscle strain in the STG after the training period decreased in the sternocleidomastoid 50%, cervical erector spinae 3%, trapezius 4%, and thoracic erector spinae 8%. In the TTG, the decrease was 41%, 30%, 20%, and 6%, respectively. In CLT, the results were similar. After a 3-mo follow-up period with intensive high +Gz flying, EMG during CLT was still lower than in baseline measurements. CONCLUSION: Both training methods were found to be effective in reducing muscle strain during in-flight and CLT, especially in the cervical muscles. There was no statistically significant difference between the training groups. Introduced exercises expand muscles' capacities in different ways and the authors recommend both strength and trampoline training programs to be included in fighter pilots' physical education programs.

Relationships Between Physical Fitness, Demands of Flight Duty, and Musculoskeletal Symptoms Among Military Pilots.

Although the mechanisms of G-induced stresses on the spinal structure of military pilots are well understood, less is known about relationships between the intensity of physical activity, fitness, occupational musculoskeletal symptoms, and the degree of resulting disabilities. During an aeromedical examination, Finnish military pilots answered a questionnaire on their flying experience, the occurrence of flight duty-related pain, the degree of resulting disabilities, and the intensity of physical activity they conducted. 195 males were selected for further analysis. They were divided into three groups, designated high G, low G, and HQ, according to their current flight duty profile. 93% of pilots who had passed fighter lead-in training reported flight duty-induced musculoskeletal disorders. The high-G group exhibited the highest aerobic capacity (p < 0.001) and muscular fitness scores (p < 0.001). The fittest individuals suffered markedly fewer disabilities than their less fit counterparts (p = 0.005). Flight hour accumulation among the subjects in the high-G group was associated (p = 0.010) with the occurrence of flight duty-induced disabilities. The fittest pilots flew aircraft that induce the heaviest accelerations. They also reported more musculoskeletal pain than the other pilots. Yet they seemed to experience fewer disabilities, which highlights the importance of physical training in the maintenance of operational readiness.

Cerebral blood flow during acceleration in flight measured with SPECT.

INTRODUCTION: Positive pressure breathing for G-protection (PBG) reduces the need for fighter pilots to use the fatiguing anti-G straining maneuver (AGSM) so that they can better endure high acceleration (+Gz). The aim of the study was to determine the differences in cerebral blood flow during flight with an extended-coverage anti-G suit (ECGS) with AGSM or with PBG. METHODS: Subjects were eight male members of the Finnish Air Force. Each was studied in the laboratory at +1 Gz and then during two identical flights in the back seat of the BAe Hawk Mk 51 jet trainer at +6 Gz, first with AGSM and second with PBG (24 mmHg). Regional cerebral blood flow (rCBF) was measured by injecting (99 m) Tc-ECD for deposition at +6 Gz, then scanning the subject in the laboratory an hour later using single photon emission computed tomography (SPECT). RESULT: The rCBF was 30% below baseline for both the AGSM and PBG. CONCLUSIONS: PBG maintained CBF at +6 Gz without the need for the fatiguing AGSM.

Specific probiotics and virological findings in symptomatic conscripts attending military service in Finland.

BACKGROUND: Viral upper respiratory tract infections occur frequently among conscripts. Probiotics have reduced viral infections in children attending day care. Limited data are available on the effects of probiotics on the nasopharyngeal presence of respiratory viruses. OBJECTIVES: To assess, whether probiotics could decrease nasopharyngeal occurrence of respiratory viruses in Finnish conscripts. STUDY DESIGN: In a randomized, double-blind, placebo-controlled 90- and 150-day intervention study, 239 nasopharyngeal swab samples were collected from 192 symptomatic conscripts receiving daily chewable probiotic tablet containing Lactobacillus rhamnosus GG and Bifidobacterium animalis ssp. lactis BB-12 (46.9%) or control tablet (53.1%) on visits to a garrison's health care center due to symptoms of infection. The presence of respiratory viruses was tested by PCR-methods, and viral findings were compared between the intervention groups. RESULTS: 184 (76.9%) nasopharyngeal samples were positive for at least one respiratory virus. Picornaviruses were the most common viruses and were detected in 155 (84.2%) of samples. Of these, 143 (92.3%) were rhinovirus-positive and 20 (12.9%) were enterovirus-positive. The control group had 83 (64%) and the probiotic group 72 (66%) picornavirus infections (p=0.79). Monthly distribution of picornaviruses showed that there were less picornavirus findings after 3 months in the probiotic group than in the control group (p=0.0069). However, probiotics did not reduce picornavirus occurrence in other months. CONCLUSIONS: Overall, probiotics did not reduce viral occurrence in symptomatic conscripts. However, probiotics decreased the presence of picornaviruses after 3 months, which may imply that probiotics play a role against viruses causing common cold. Further investigations are necessary to clarify the mechanisms involved in order to target specific probiotics on specific respiratory viruses.

Effects of head and extracranial injuries on serum protein S100B levels in trauma patients.

BACKGROUND: Serum protein S100B determinations have been recently suggested as markers of traumatic brain injury. However, little is known about the effects of extracranial injuries on S100B levels in trauma patients. METHODS: We studied 224 patients with head trauma (54 of whom also had extracranial injuries), 155 patients with various types of extracranial injuries, and 8 healthy pilots exposed to high Gz forces. The head trauma patients had either no brain injury (n = 35), mild brain injury (n = 165), or moderate to severe brain injury (n = 24). The extracranial injuries were divided into small and large injuries. Serum protein S100B levels were determined from samples taken within 6 hours after the trauma event. RESULTS: The head trauma patients had a significantly higher median S100B (0.17 microg/L) than the patients with extracranial injuries (0.07 microg/L) (p < 0.001). Serum S100B levels also correlated with the severity of brain injury (p < 0.001), the highest values occurring in the patients with moderate to severe brain injury (1.27 microg/L). However, large extracranial injuries also elevated S100B levels (0.35 microg/L), whereas small extracranial injuries in the absence of head trauma did not significantly affect S100B levels (0.07 microg/L). Above the cutoff level of 0.13 microg/L, there were 61% of the head trauma patients and 26% of those with extracranial injuries (Pearson chi test, p < 0.001). However, only 4% of the patients with purely extracranial injuries had a concentration of S100B above the cutoff level of 0.50 microg/L, whereas the head trauma patients with moderate to severe brain injury exceeded this cutoff in 67% of the cases. Exposure to high Gz forces did not influence serum S100B levels in healthy individuals. CONCLUSION: We conclude that serum S100B is a sensitive marker of brain injury, which correlates with the severity of the injury. Large extracranial injuries also elevate S100B levels. However, S100B has a high negative predictive power, and the finding of a normal S100B value shortly after trauma should thus exclude significant brain injury with a high accuracy.