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Biomedical subjects

H Pekkarinen

Publications and source records attributed to H Pekkarinen.

16 recordsLinked to original sources
PubMed1999

Short-term variations in oscillatory and spirometric lung function parameters of non-asthmatic adults.

Oscillatory respiratory resistance (Rrsfo) at 8 Hz was compared to flow-volume spirometry with regard to immediate, within-day, day-to-day and week-to-week variations in seven female and four male non-smoking, non-asthmatic volunteers. The lung functions were measured at 08:00, 12:00, 16:00 and 20:00 h on each of the four study days, i.e. two consecutive days in two consecutive weeks. During each visit there were three immediately repeated measurements of Rrsfo, followed by three spirometric recordings. The intra-subject coefficient of variation (Coeffvar) for the immediately repeated measurements was largest for Rrsfo (11.8%). When a simple reliability index (+/- 2 SD of the differences between the repeated measurements) was applied to the Rrsfo data, the Coeffvar reduced to 7.5%. In spirometry, the airflow parameters at defined lung volumes showed larger immediate variations (MEF50 = 5.6%, MEF25 = 8.3%, MMEF = 4.4%) than FEV1 (1.5%) and PEF (3.2%). The within-day variations were larger than the day-to-day or week-to-week variations, and the variations were largest in Rrsfo. A significant diurnal pattern was shown in spirometric parameters but not in Rrsfo. About 38% of the total variance in Rrsfo was due to variation within subjects, while the corresponding proportions in spirometric parameters were 1.8-18.4%. In conclusion, Rrsfo showed larger intrasubject variations than the spirometric parameters at all time intervals. Application of a simple reliability index and standardization of the time of day of the measurement reduced the variations and improved the quality of the Rrsfo data.

Adult↗
PubMed1998

Effect of cold air on exercise capacity in COPD: increase or decrease?

STUDY OBJECTIVE: To clarify the effect of cold air on exercise capacity in COPD. DESIGN: Cycle ergometer tests under different environmental conditions. SETTING: Pulmonary function laboratory and an environmental chamber at a university hospital. PARTICIPANTS: Eighteen patients with stable COPD; 14 completed the study. INTERVENTIONS: A preliminary cycle ergometer test followed by two incremental, symptom-limited cycle ergometer tests, one at 24 degrees C and the other at -20 degrees C. MEASUREMENTS: On the first study day: arterial blood gas analysis, 12 to 15 s maximal voluntary ventilation, maximal expiratory flow-volume curves before and 1 h after inhalation of 80 microg of ipratropium bromide, and diffusion capacity of the lung. During the exercise challenges: spirometric indices, minute ventilation (VE), oxygen consumption (VO2), carbon dioxide production (VCO2), facial skin temperature, and heart rate. The feeling of dyspnea was assessed with a visual analogue scale. RESULTS: The maximal work load was 87.5+/-7.3 W at -20 degrees C compared with 96.4+/-6.9 W at 24 degrees C (p<0.05). Accordingly, the exercise duration was shorter in the cold. Exercise dyspnea was more severe in the cold at equal work loads. The shortening of exercise duration induced by cold air correlated with the enhancement of exercise dyspnea. Furthermore, cold air cooled the facial skin and induced immediate bronchoconstriction. VE, VO2, VCO2, and heart rate did not differ between the warm and cold challenges. CONCLUSIONS: Cold air decreases exercise capacity in COPD, probably by increasing exercise dyspnea.

Adult↗
PubMed1994

Effect of whole-body exposure to cold and wind on lung function in asthmatic patients.

To assess the effect of subfreezing temperature and wind on lung function in asthmatic patients, an exposure to subfreezing temperature at rest, a moderate exercise challenge at subfreezing temperature, and a similar exercise challenge at room temperature were performed in 19 stable asthmatic subjects in an environmental chamber with an artificial wind. The mean maximal falls in FEV1 were 5.3, 11.7, and 4.8 percent, respectively. The two challenges at subfreezing temperature caused statistically significant changes in FEV1, but the exercise challenge at room temperature had no effect. A large variation in the sensitivity to cold was found. The time courses of the responses varied between the challenges, suggesting at least partially different mechanisms. The results indicate that even moderate exercise can cause severe bronchoconstriction in certain stable asthmatic subjects at climatic conditions similar to the Scandinavian winter. The importance of reflex mechanisms causing bronchoconstriction in physiologic conditions is discussed.

Adult↗
PubMed1993

Influence of the menstrual cycle and oral contraceptives on thermoregulatory responses to exercise in young women.

Thermoregulatory responses to exercise in relation to the phase of the menstrual cycle were studied in ten women taking oral contraceptives (P) and in ten women not taking oral contraceptives (NP). Each subject was tested for maximal aerobic capacity (VO2max) and for 50% VO2max exercise in the follicular (F) and luteal (L) phases of the menstrual cycle. Since the oral contraceptives would have prevented ovulation a quasi-follicular phase (q-F) and a quasi-luteal phase (q-L) of the menstrual cycle were assumed for P subjects. Exercise was performed on a cycle ergometer at an ambient temperature of 24 degrees C and relative air humidity of 50%. Rectal (Tre), mean skin (Tsk), mean body (Tb) temperatures and heart rate (fc) were measured. Sweat rate was estimated by the continuous measurement of relative humidity of air in a ventilated capsule placed on the chest, converted to absolute pressure (PH2Ochest). Gain for sweating was calculated as a ratio of increase in PH2Ochest to the appropriate increase in Tre for the whole period of sweating (G) and for unsteady-state (Gu) separately. The VO2max did not differ either between the groups of subjects or between the phases of the menstrual cycle. In P, rectal temperature threshold for sweating (Tre,td) was 37.85 degrees C in q-L and 37.60 degrees C in q-F (P < 0.01) and corresponded to a significant difference from Tre at rest. The Tre, Tsk, Tb and fc increased similarly during exercise in q-F and q-L. No menstrual phase-related differences were observed either in the dynamics of sweating or in G.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Identification of health status dimensions in a working-age population. An exploratory study.

With regard to health care there is a growing demand for comprehensive and reliable instruments of general health status measurement. In the Finnish Healthy Village Study, 427 men and 366 women of working age participated in a comprehensive health examination that included more than 120 physical, psychological, and social health status variables. On the basis of minimum correlation values, 37 health status variables were chosen for factor analytic study. Principal component factor analysis with varimax rotation identified six dimensions of health status: physical functioning, emotional state, perceived health, anthropometric state and blood pressure, social functioning, and biochemical state. These six factors accounted for 46% of the total variance of health status variables. Health profile analysis of both men and women revealed the same dimensions but in different order. Men ranked their self-rated general health more closely with their physical functioning, whereas women ranked it with perceived health. The identification of general health status dimensions has implications for planning health promotion programs and evaluating their outcomes.

Adult↗
PubMed1992

Epidemiology of vitamins A, E, D and C in rural villages in Finland: biochemical, nutritional and socioeconomical aspects.

We carried out an extensive health profile analysis in spring-winter 1986 in four Eastern Finnish rural villages as a part of the Healthy Village Study. Altogether, 793 people at working age (20-64 years of age, 427 men and 366 women) participated (80%). Serum lipids (total cholesterol, HDL-cholesterol and triglycerides) and plasma vitamins (vitamin A, D, E and C) were measured as biochemical indicators of health. The dietary habits were reflected in high serum total cholesterol, and in low plasma vitamin C (ascorbic acid, mean 34.4 mumol/l in men, and 51.2 mumol/l in women). The plasma levels of the other vitamins studied were, in general, satisfactory. The mean plasma concentration of vitamin A (retinol) was 2.70 mumol/l in men, and 2.23 mumol/l in women. The gender, high body weight and the use of animal fats had the strongest association to apparent plasma retinol concentrations. The corresponding plasma concentrations of vitamin D (25-hydroxy-D) were 34.1 nmol/l and 35.4 nmol/l, and vitamin E (d-alpha-tocopherol) 22.1 mumol/l and 22.2 mumol/l. Vitamin D deficiency (plasma 25-OHD less than 12.5 nmol/l) was seen in 5% of the subjects. A good vitamin D status was correlated with the use of vitamin supplements, and, surprisingly, with the frequent consumption of alcohol.

Adult↗
PubMed1991

Fish diet and physical fitness in relation to membrane and serum lipids, prostanoid metabolism and platelet aggregation in female students.

The effects of a 14-week fish diet and exercise programme on lipid metabolism and platelet aggregation in healthy female students (n = 99) were studied. The subjects were divided into four groups: a control group, a fish diet group (3.5 meals containing fish per week, 0.9 g n-3 fatty acids per day), an exercise group (at least three training sessions per week) and a combined fish diet and exercise group. The proportion of n-3 fatty acids increased at the expense of n-6 fatty acids in platelets and erythrocyte ghosts in the fish diet groups. Serum triglyceride concentrations tended to decrease in the fish diet and exercise groups and a significant decrease was found in the combined fish diet and exercise group (13%, P less than 0.05). No significant changes took place in the other serum lipid and apolipoprotein concentrations. Platelet production of thromboxane B2, plasma 6-keto-PGF1 alpha concentrations and adenosine 5'-diphosphate (ADP)-induced platelet aggregation also remained unchanged in all groups during the study. However, an inverse correlation was found between physical fitness (maximal oxygen uptake and maximal exercise intensity) and serum triglycerides, total cholesterol, low density lipoprotein cholesterol and platelet aggregation. This suggests that improved physical fitness is related to beneficial changes in serum lipid concentrations and to a decreased aggregation tendency of platelets. The responses of the female subjects to a fish diet were smaller when compared to earlier studies on male subjects. This suggests that there are sex differences in the efficiency of n-3 fatty acids in modifying lipid metabolism.

6-Ketoprostaglandin F1 alpha↗
PubMed1991

Comparison in men of physiological responses to exercise of increasing intensity at low and moderate ambient temperatures.

In six male subjects the sweating thresholds, heart rate (fc), as well as the metabolic responses to exercise of different intensities [40%, 60% and 80% maximal oxygen uptake (VO2max)], were compared at ambient temperatures (Ta) of 5 degrees C (LT) and 24 degrees C (MT). Each period of exercise was preceded by a rest period at the same temperature. In LT experiments, the subjects rested until shivering occurred and in MT experiments the rest period was made to be of exactly equivalent length. Oxygen uptake (VO2) at the end of each rest period was higher in LT than MT (P less than 0.05). During 20-min exercise at 40% VO2max performed in the cold no sweating was recorded, while at higher exercise intensities sweating occurred at similar rectal temperatures (Tre) but at lower mean skin (Tsk) and mean body temperatures (Tb) in LT than MT experiments (P less than 0.001). The exercise induced VO2 increase was greater only at the end of the light (40% VO2max) exercise in the cold in comparison with MT (P less than 0.001). Both fc and blood lactate concentration [1a]b were lower at the end of LT than MT for moderate (60% VO2max) and heavy (80% VO2max) exercises. It was concluded that the sweating threshold during exercise in the cold environment had shifted towards lower Tb and Tsk. It was also found that subjects exposed to cold possessed a potentially greater ability to exercise at moderate and high intensities than those at 24 degrees C since the increases in Tre, fc and [1a]b were lower at the lower Ta.

Adolescent↗
PubMed1990

Thermoregulatory responses to exercise at low ambient temperature performed after precooling or preheating procedures.

Seven male skiers exercised for 30 min on a cycle ergometer at 50% of maximal oxygen uptake and an ambient temperature of 5 degrees C. The exercise was preceded either by cold exposure (PREC) or active warming-up (PREH). The data were compared with control exercise (CONT) performed immediately after entering the thermal chamber from a thermoneutral environment. Cold exposure resulted in negative heat storage (96.1 kJ.m-2, SE 5.9) leading to significantly lower rectal, mean body and mean skin temperatures at the onset of exercise in PREC, as compared to PREH and CONT. The PREC-PREH temperature differences were still significant at the end of the exercise period. During exercise in the PREC test, oxygen uptake was higher than in PREH test (32.8 ml.kg-1.min-1, SE 1.5 vs 30.5 ml.kg-1.min-1, SE 1.3, respectively). Heart rate showed only a tendency to be higher in PREC than in PREH and CONT tests. In the PREH test skin and body temperatures as well as sweat rate were already elevated at the beginning of exercise. Exercise-induced changes in these variables were minimal. Heat storage decreased with the duration of the exercise. Exercise at low ambient temperature preceded by a 30-min rest in a cold environment requires more energy than the same exercise performed after PREH.

Adolescent↗
PubMed1989

Effect of submaximal exercise at low temperatures on pulmonary function in healthy young men.

In order to understand more fully the effect on pulmonary function of whole body exposure to cold during submaximal exercise, we measured pulmonary function indices in ten healthy male students and ten healthy male forestry workers of similar age following submaximal treadmill walking at different temperatures in a climatic chamber. After measuring the maximal aerobic capacity with a cycle ergometer test, the subjects had to walk on four separate occasions in the climatic chamber at an intensity of 70%-75% of their individual maximal heart rate; the first at normal room temperature and then randomly, either at 0 degrees C or at -20 degrees C, and vice versa. The duration of each walk was 8 min. Finally, each subject had to walk in the chamber at -20 degrees C for 17 min. Flow volume spirometry was performed at room temperature 1, 5, 10, and 20 min after exercise and the values were compared to baseline values taken prior to the last walking test. There were only minor changes in pulmonary function indices following exercise at different temperatures. Only one student showed a reduction of over 15% in peak expiratory flow rate after an 8-min walk at -20 degrees C. It seems that submaximal exercise of short duration, even at a temperature as low as -20 degrees C, does not impair pulmonary function in healthy young men.

Adult↗
PubMed1989

Physiological profiles of young boys training in ballet.

In order to evaluate physiological characteristics in young male ballet dancers, 27 boys (aged 9 to 16 years) who participated in a boys' dance course during the Kuopio Dance and Music Festival in June 1988 were studied. In general, the boys had started dancing at the age of 8.6 years and had been training for 4.1 years. They had, on average, three dancing sessions per week and the mean time spent on dancing was four hours per week. In the study, some anthropometric measurements were taken, the maximal oxygen uptake (VO2 max) was measured by a cycle ergometer test and the explosive strength and the mechanical power of lower extremities were evaluated by a jumping test. The results indicate that boys who train in ballet are in general moderately lean, have relatively small body size and a high degree of flexibility. The younger boys especially have only moderate aerobic power, but both explosive strength and mechanical power in leg muscles are good in ballet trained boys.

Adolescent↗
PubMed1989

On-line determination of anaerobic threshold with rms-EMG.

1. On-line monitoring of surface rms-EMG for detecting the anaerobic threshold during a cycle ergometer test was evaluated and compared with blood lactate and ventilatory parameters in 12 healthy icehockey players. 2. Dislinearity of increase in blood lactate level, ventilatory parameters and myoelectrical activity was observed at the mean work level of 300 (range 270-330) watts in each case. 3. The linearity disappeared at the same time in the rms-EMG-load ratio in working quadriceps and gastrocnemius muscles while also in nonworking frontalis muscle a change in EMG level was noticed. 4. The break point in rms-EMG did not correlate with the changes in skin humidity and temperature. No change was observed in spectral properties of the myoelectrical signals. 5. The rms-EMG follow-up is easier to perform than measurements of blood lactate and ventilatory parameters in the determination of anaerobic threshold.

Adolescent↗
PubMed1982

Results of long-term ECG monitoring in patients submitting to tonsillectomy under local anaesthesia.

Sixteen patients submitted to tonsillectomy under local anaesthesia in a sitting position were studied electrocardiographically. Continuous ECG monitoring was used to discover whether there were any electrocardiographic changes, especially ventricular extrasystolies, during the operation. During the entire registration time, which varied from 4.5-22.5 hours, ventricular extrasystolies were found in seven of the sixteen patients. During the operation only a single VES was seen, in one patient. We conclude that tonsillectomy done under local anaesthesia is safe from the cardiovascular point of view.

Adolescent↗