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.

Muscular, cardiorespiratory and thermal strain of mast and pole workers.

This field study evaluated the level of muscular, cardiorespiratory and thermal strain of mast and pole workers. We measured the muscular strain using electromyography (EMG), expressed as a percentage in relation to maximal EMG activity (%MEMG). Oxygen consumption (VO2) was indirectly estimated from HR measured during work and expressed as a percentage of maximum VO2 (%VO2max). Skin and deep body temperatures were measured to quantify thermal strain. The highest average muscular strain was found in the wrist flexor (24 ± 1.5%MEMG) and extensor (21 ± 1.0%MEMG) muscles, exceeding the recommendation of 14%MEMG. Average cardiorespiratory strain was 48 ± 3%VO2max. Nearly half (40%) of the participants exceeded the recommended 50%VO2max level. The core body temperature varied between 36.8°C and 37.6°C and mean skin temperature between 28.6°C and 33.4°C indicating possible occasional superficial cooling. Both muscular and cardiorespiratory strain may pose a risk of local and systemic overloading and thus reduced work efficiency. Thermal strain remained at a tolerable level.

Military service-aggravated asthma improves at two-year follow-up.

BACKGROUND: During military service young men (age 19-21 years) are exposed to many predisposing factors for asthma. We aimed to study the short-term prognosis of asthma after the military service. METHODS: All 216 men with verified asthma in 2004-2005 from the register of the Central Military Hospital were included in the study. A questionnaire was mailed to them in autumn 2007 and the 146 responders (68%) formed the final study population. Asthma severity was evaluated during military service according to the medical records of the subjects and two years later based on the questionnaire using modified GINA guidelines. The results on lung function and allergy tests during military service and asthma history were used as predictors of asthma severity at two-year follow-up. RESULTS: Two groups of asthmatics were identified: those who already had asthma when entering the military service (n=71, 48.6%) and those, who had a new onset of asthma during the service (n=75, 51.4%). Overall asthma was less severe at two-year follow-up than during military service (p=0.036). Both during military service and at two-year follow-up, asthma was milder among the men, who had a new onset of asthma during military service. Atopy (p=0.002), number of positive skin-prick tests (p=0.005) and higher total serum IgE (p=0.001) were significant predictors for persistent asthma at follow-up. CONCLUSIONS: Asthma, which had aggravated or started during military service, was significantly less severe two years later. The degree of atopy was a major determinant of the two-year prognosis of asthma after military service.

Incidence of asthma in twelve thousand Finnish adults born in 1966.

OBJECTIVES: Asthma prevalence is increasing in many countries. Some recent articles, however, claim that this tendency is drawing to an end. Hence, the incidence of persistent asthma was drawn from a birth cohort study in Finland. MATERIALS AND METHODS: A cohort of 6107 men and 5839 women was followed from 1981 to 2004. The participants were members of the Northern Finland Birth Cohort 1966 Study (NFBC-66). The single-year birth cohort was followed from the age of 15 to 38 years by means of a complete register held by the national Social Insurance Institute (SII) in Finland. Within the register data, an incident case of asthma was defined by the received right for reimbursement for asthma medication from the SII. RESULTS: Over a 23-year follow-up period, persistent asthma occurred in 466 study participants of whom 54% were women. The incidence of persistent asthma increased from the rate of 10 cases per 10 000 person-years at the age of 15-20 years to 21 cases per 10 000 person-years at the age of 36-38 years. In females, a peak of incidence rate was found between the age of 31 and 35 years, up to 27 cases per 10 000 person-years. CONCLUSIONS: The follow-up of a population-based birth cohort among young working aged Finns shows the increasing incidence rate of persistent asthma. In recent years, however, a decline in new cases of asthma occurred in females aged between 36 and 38 years.

The occurrence of frostbite and its risk factors in young men.

OBJECTIVES: Previous studies have paid little attention to the occurrence of frostbites and related risk factors. The purpose of this study is to analyse the life-time occurrence of frostbite in young men and its association with the cold-provoked white finger syndrome (CPWF), smoking and hand vibration. METHODS: The study population consisted of 5839 Finnish men aged 17-30 years entering military service. Data was collected for cases of first-degree, or more severe, frostbite affecting the head and extremities. Logistic analysis was used to assess the risk of frostbite with respect to CPWF, smoking and hand vibration. RESULTS: The life-time and annual occurrences of frostbite were 44% and 2.2%, respectively (n = 2555). 2333 subjects (41%) had suffered first-degree freezing injury and 671 (12%) suffered severe injury at some time in their lives. The sites most prone to frostbite were the head, 1668 cases (31%), followed by the hands, 1154 (20%), and the feet, 810 (15%). The risk for frostbite in different body parts was increased among the subjects with CPWF (95% CI: 1.66 to 3.87), regular smokers (95% CI: 1.02 to 3.15) and those exposed to vibration (95% CI: 1.07 to 4.03). CONCLUSIONS: A synergistic increase of frostbite was reported between CPWF and regular smokers, and between CPWF and hand/arm vibration in both exposure classes analysed. The life-time occurrence of frostbite among young healthy men was high. Frostbite, and its association with CPWF, smoking and hand/arm vibration should be noted by the health care personnel in circumpolar countries.

Does living in a cold climate or recreational skiing increase the risk for obstructive respiratory diseases or symptoms?

OBJECTIVES: Respiratory symptoms and obstructive pulmonary diseases experienced during exercise and in cold weather were analysed in a large postal questionnaire study of a general adult population living in a cold climate. The aim of this study was to assess the prevalence of shortness of breath (SOB) during exercise, or in cold weather, and to find out if the risks (odds ratio=OR) for asthma, chronic bronchitis, or SOB during exercise, or in cold weather, were affected by recreational cross-country skiing, or by outdoor work in a cold climate. RESULTS: Of the 7937 invited persons, 84% responded; 876 of them were outdoor workers and 1497 were recreational cross-country skiers. Of the non-smoking responders, asthmatic subjects had the highest prevalence of SOB during exercise in cold weather (78%-82%), but allergic and bronchitic persons also had significantly higher prevalence rates (22%-38% and 27%-59%, respectively) than healthy persons (10%-19%). In all categories, the prevalence of SOB was significantly higher among current smokers than among ex- or non-smokers. Risk factor analysis revealed increased risks for respiratory conditions among those who had a family history of obstructive airway disease, or allergy. Skiers did not have a significantly increased risk for asthma, or respiratory symptoms. Among outdoor workers the risk for SOB during exercise in cold weather, OR 1.23 (CI 1.03-1.47), and for chronic bronchitis, OR 1.77 (CI 1.21-2.60), was higher than among indoor workers. CONCLUSIONS: In conclusion, the risk for chronic bronchitis and bronchitic symptoms was elevated among outdoor workers, but not among regular recreational cross-country skiers, and the risk for asthma was not significantly elevated by regular exercising, or by working in a cold climate.