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  • 1.
    de Bruijn, Robert
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Richardson, Matthew
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Haughey, Helena
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Björklund, Glenn
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Pettersson, Sofia
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Schagatay, Erika
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    High hemoglobin levels in divers may be a result of apnea induced EPO-production2005In: FASEB JOURNAL, 2005, p. A211-A212Conference paper (Refereed)
    Abstract [en]

    Oxygen storage capacity is important for apneic duration and affects performance in endurance sports. We studied if hemoglobin concentration (Hb) was different in divers compared to endurance athletes and untrained subjects and if any differences could be connected to training-induced erythropoietin (EPO) -production. We first compared Hb in 3 groups of subjects: 13 elite apneic divers (35±4 years), 13 elite cross-country skiers (20±1 years) and 23 untrained subjects (29±1 years) with similar weight and height. After 20 min of horizontal rest blood samples were drawn and analysed for Hb using standard methods. In a second experiment, we compared EPO levels before and after a series of 15 maximal apneas in air in 9 previously untrained volunteers (302 years). Apneas were spaced by 2 minutes, the last minute with hyperventilation to produce durations long enough to induce hypoxia. Values were also compared to the EPO levels of a control day without apneas. The apneic divers had higher Hb than untrained subjects (P<0.05) and skiers (P<0.01). After apnea training in untrained subjects EPO levels increased in all subjects, with a mean peak value after 3 h, where the increase was 135 % of the pre apnea value (P<0.05). No increase was observed during the same time period of the control day. We concluded that higher Hb levels in apneic divers may be a result of enhanced EPO-production due to the apnea training.

  • 2.
    de Bruijn, Robert
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Richardson, Matthew
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Haughey, Helena
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Holmberg, Hans-Christer
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Björklund, Glenn
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Schagatay, Erika
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Hemoglobin levels in elite divers, elite skiers and untrained humans2004Conference paper (Other academic)
  • 3. Richardson, M
    et al.
    de Bruijn, Robert
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Haughey, Helena
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Andersson, J
    Schagatay, Erika
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    The incidence of hematocrit increase during apnea in non divers: European Underwater and Baromedical Society (EUBS) meeting Copenhagen, Denmark2003Conference paper (Other academic)
  • 4.
    Richardson, Matthew
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    de Bruijn, Robert
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Holmberg, Hans-Christer
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Björklund, Glenn
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Haughey, Helena
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Schagatay, Erika
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Increase of hemoglobin concentration after maximal apneas in divers, skiers and untrained humans2005In: Canadian Journal of Applied Physiology, ISSN 1066-7814, Vol. 30, no 3, p. 276-281Article in journal (Refereed)
    Abstract [en]

    Apnea is physiologically stressful and can within a short time frame pose a threat to survival. To sustain prolonged apnea, oxygen use should be minimized and its storage maximized. Two mechanisms known to have this effect are the cardiovascular diving response, directing the available oxygen selectively to the heart and brain, and spleen contraction increasing the circulating erythrocyte volume and thereby gas storage capacity. Spleen contraction is also observed after maximal exercise, and is thought to enhance aerobic performance. While the cardiovascular diving response is known to be more pronounced after apnea training, spleen contraction has not been studied in conjunction with apnea training or other types of training. The aim of the present investigation is to study the hematological responses to apnea performed during rest by elite apneic divers, by elite cross-country skiers and by untrained subjects. After 20 min of rest, subjects performed 3 maximal apneas spaced by 2 min normal breathing intervals. Blood samples were drawn before, directly after, and 10 min after the apnea series and hemoglobin concentration was measured. All groups responded to maximal apneas with an increase in hemoglobin concentration, which had disappeared after 10 min of recovery. The increase in hemoglobin concentration was more pronounced in the apneic divers (4g/L) than in skiers (3g/L) and untrained subjects (2g/L; P < 0.05). All groups prolonged their apneic times through the series, but the increase was most evident for the divers versus both the skiers (P < 0.05) and untrained subjects (P < 0.01). The results suggest that these responses could be more pronounced as a result of apnea training.

  • 5.
    Richardson, Matthew
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Schagatay, Erika
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    de Bruijn, Robert
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Haughey, Helena
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Hematological response pattern associated with maximal-duration apnea series in untrained subjects: Annual Meeting of the European Underwater and Baromedical Society, Copenhagen, Denmark.2003Conference paper (Other academic)
    Abstract [en]

    Background: In addition to the human cardiovascular ‘diving response’, i.e., bradycardia and peripheral vasoconstriction during apnea, recent studies have shown that spleen contraction also occurs during repeated apneas. This latter response may serve to expel erythrocytes into the circulation to promote gas transportation. However, prospective changes in blood parameters after repeated apneas have yet to be systematically described. As is the case with diving response parameters, some individuals may have stronger haematological changes from performing apneic series than others. These variations need to be considered in future studies of the function of the spleen and blood components during apnea. The present study was aimed to describe the haematological response pattern associated with repeated maximal apneas in healthy non-divers. Methods: After 20 min of rest, 46 healthy untrained subjects of both sexes performed three maximal apneas, spaced by two minutes rest and normal breathing. Blood samples were taken before, within 1 minute after, and 10 minutes after the apneic series and analyzed for changes in haemoglobin (Hb) concentration and hematocrit (Hct). Results: Pre-apnea Hb concentration (mean±SE) was normally distributed (147.1±1.6 g/L). An increase of 2.1±0.3% in the Hb value was seen immediately post-series, followed by a decrease from this value of 1.8±0.3% at 10 minutes post-series. Pre-apnea hematocrit (41.2±0.6 percent) showed a similar increase immediately post-series of 3.2±0.8% followed by a decrease of 1.6±0.4% from this value at 10 minutes post-series. Classifying subjects as strong responders (above 75th percentile) and weak responders (below 25th percentile) resulted in mean increases in Hb and Hct above pre-apneic values of 4.7±0.4% and 7.1±2.1%, respectively for strong responders, and -0.5±0.4 and 0.5±0.6, respectively for weak responders. Conclusion: Significant increases in Hb and Hct values occur immediately after a maximal apneic series, followed by a return towards baseline values after 10 minutes. These increases may be due to the spleen contraction as demonstrated in previous research. Furthermore, some subjects appear to respond more strongly than others, and pre-screening for these types of responders may be judicious in future testing. The mechanism(s) underlying the strength of these haematological responses warrants further investigation.

  • 6.
    Schagatay, Erika
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Haughey, Helena
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Reimers, J
    Speed of spleen volume changes evoked by serial apneas2005In: European Journal of Applied Physiology, ISSN 1439-6319, E-ISSN 1439-6327, Vol. 93, no 4, p. 447-452Article in journal (Refereed)
    Abstract [en]

    Diving mammals may enhance dive duration by injecting extra erythrocytes into the circulation by spleen contraction. This mechanism may also be important for apneic duration in humans. We studied the speed and magnitude of spleen volume changes evoked by serial apneas, and the associated changes in hematocrit (Hct) and hemoglobin (Hb) concentration, diving response and apneic duration. Three maximal apneas separated by 2 min rest elicited spleen contraction in all ten subjects, by a mean of 49 (27) ml (18%; P<0.001). During the same period, Hct and Hb rose by 2.2 and 2.4% respectively (P<0.01 and P<0.001), and apneic duration rose by 20 s (22% P<0.05). The mean heart rate reduction of the diving response was 15%, which remained the same throughout the apnea series. While the diving response was completely reversed between the apneas, spleen size was not recovered until 8–9 min after the final apnea corresponding with recovery of Hct and Hb. Thus, although the spleen contraction may be associated with the cardiovascular diving response, it is likely to be triggered by different mechanisms, and it may remain activated between dives spaced by short pauses. The two adjustments may provide a fast, quickly reversed, and a slow, but long-lasting, way of shifting to a diving mode in humans

  • 7.
    Schagatay, Erika
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Haughey, Helena
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Reimers, J
    Spleen volume changes evoked by serial apneas: Underwater and Baromedical Society (EUBS) meeting Copenhagen2003Conference paper (Other academic)
  • 8.
    Schagatay, Erika
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Richardson, Matt
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    de Bruijn, Robert
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Haughey, Helena
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Holmberg, Hans Christer
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Naturlig bloddopning vid fysiologisk stress2004In: Svensk idrottsforskning, ISSN 1103-4629, Vol. 13, no 1, p. 18-21Article in journal (Other academic)
  • 9.
    Vigetun, Helena
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering and Sustainable Development.
    Appelberg, Jonas
    Sundsvall Hospital.
    Forsberg, Tomas
    Kaldensjö, Magnus
    Schagatay, Erika
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering and Sustainable Development.
    Diving response and Hb elevation during voluntary apnea in patients with obstructive sleep apnea.2011In: SFSS congress proceedings, 2011Conference paper (Refereed)
  • 10.
    Vigetun-Haughey, Helena
    et al.
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences. Capio St Gorans Hosp, Dept Clin Physiol, Stockholm, Sweden.
    Appelberg, Jonas
    Sundsvall Hosp, Dept Res & Dev, Vasternorrland Cty Council, Sundsvall, Sweden.
    Forsberg, Tomas
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Kaldensjö, Magnus
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Schagatay, Erika
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Voluntary apnea evokes diving responses in obstructive sleep apnea patients2015In: European Journal of Applied Physiology, ISSN 1439-6319, E-ISSN 1439-6327, Vol. 115, no 5, p. 1029-1036Article in journal (Refereed)
    Abstract [en]

    Two potentially protective responses to apnea were studied in obstructive sleep apnea (OSA) patients; the diving response and the increase in Hb concentration [Hb] via spleen contraction. Eight OSA patients and ten healthy controls performed apneas in air (A) and apneas with facial immersion in 15 A degrees C water (FIA) after inspiration and without prior hyperventilation. In each condition, subjects performed three apneas of maximal voluntary duration spaced by 2 min of rest. Cardiorespiratory parameters were measured non-invasively, and venous blood samples for [Hb] analysis were drawn before and after apneas. Mean (SD) apnea durations were similar between groups (NS). In controls, the heart rate (HR) reduction was 10 +/- A 10 % at apnea and 19 +/- A 10 % in FIA (P < 0.05). In OSA patients, however, the fall in HR was the same in both conditions, 13 +/- A 10 and 14 +/- A 8 % for A and FIA, respectively (NS). In controls, the [Hb] increase was the same in A and FIA (2.2 +/- A 2.9 and 2.1 +/- A 2.2 %), while in OSA the [Hb] increase was greater during FIA compared to A (3.3 +/- A 2.2 and 1.4 +/- A 0.9 %; P < 0.05). Apnea induces a diving response and [Hb] increase in both groups. OSA patients did not show the typical training effect of the diving response seen in apnea divers despite their frequent nocturnal apneas. However, they also deviated from normal controls in response pattern; face immersion enhanced the cardiovascular diving response in controls but not in OSA, while the hematological response was enhanced by face immersion only in OSA patients.

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