Vuorokausirytmin häiriöt ja terveys

The doctoral thesis defined connections between circadian rhythm disruptions and health problems. Sleep debt, jet-lag, shift work, as well as transitions into and out of the daylight saving time may lead to circadian rhythm disruptions. Disturbed circadian rhythm causes sleep deprivation and decrease of mood and these effects may lead to higher accident rates and trigger mental illnesses. Circadian clock genes are involved in the regulation of the cell cycle and metabolism and thus unstable circadian rhythmicity may also lead to cancer development. In publications I-III it was explored how transitions into and out of the daylight saving time impact the sleep efficiency and the rest-activity cycles of healthy individuals. Also it was explored whether the effect of transition is different in fall as compared to spring, and whether there are subgroup specific differences in the adjustment to transitions into and out of daylight saving time. The healthy participants of studies I-III used actigraphs before and after the transitions and filled in the morningness-eveningness and seasonal pattern assessment questionnaires. In publication IV the incidence of hospital-treated accidents and manic episodes was explored two weeks before and two weeks after the transitions into and out of the daylight saving time in years 1987-2003. In publication V the relationship between circadian rhythm disruption and the prevalence of Non-Hodgkin lymphoma was studied. The study V consisted of all working aged Finns who participated in the national population census in 1970. For our study, all the cancers diagnosed during the years 1971-1995 were extracted from the Finnish Cancer Register and linked with the 1970 census files. In studies I-III it was noticed that transitions into and out of the daylight saving time disturbs the sleep-wake cycle and the sleep efficiency of the healthy participants. We also noticed that short sleepers were more sensitive than long sleepers for sudden changes in the circadian rhythm. Our results also indicated that adaptation to changes in the circadian rhythm is potentially sex, age and chronotype-specific. In study IV no significant increase in the occurrence of hospital treated accidents or manic episodes was noticed. However, interesting observations about the seasonal fluctuation of the occurrence rates of accidents and manic episodes were made. Study V revealed that there might be close relationship between circadian rhythm disruption and cancer. The prevalence of Non-Hodgkin lymphoma was the highest among night workers. The five publications included in this thesis together point out that disturbed circadian rhythms may have adverse effect on health. Disturbed circadian rhythms decrease the quality of sleep and weaken the sleep-wake cycle. A continuous circadian rhythm disruption may also predispose individuals to cancer development. Since circadian rhythm disruptions are common in modern society they might have a remarkable impact on the public health. Thus it is important to continue circadian rhythm research so that better prevention and treatment methods can be developed. Keywords: Circadian rhythm, daylight saving time, manic episodes, accidents, Non-Hodgkin lymphoma 11Väitöskirjatyössä kartoitettiin vuorokausirytmin häiriöiden terveysvaikutuksia. Vuorokausirytmin häiriintymistä aiheuttavat useat tekijät, joista yleisimpiä ovat unen puute, vuorotyö, aikaerorasitus sekä kesä- ja talviaikaan siirtyminen. Vuorokausirytmin häiriöit voivat aiheuttaa univaikeuksia, lisätä onnettomuuksien määrää ja laukaista mielenterveysongelmia. Koska vuorokausirytmiä säätelevät kellogeenit osallistuvat solusyklin säätelyyn ja aineenvaihduntaan, epävakaa vuorokausirytmi voi häiritä myös solunjakautumista ja johtaa syövän syntyyn. Viimeaikaisissa tutkimuksissa onkin saatu viitteitä siitä, että vuorokausirytmin häiriöt altistavat tietyille syöpäsairauksille. Tutkimuksissa I-III kartoitettiin, miten kesä- ja talviaikaan siirtyminen vaikuttaa terveiden koehenkilöiden unen laatuun ja uni-valverytmiin, ovatko vuorokausirytmin häiriintymisen vaikutukset erilaisia keväisin ja syksyisin, ja onko muuttuneeseen vuorokausirytmiin sopeutumisessa alaryhmien välisiä eroja. Tutkimuksiin I-III osallistuneet koehenkilöt käyttivät tutkimuksen ajan aktigrafeja ja vastasivat aamuisuus-iltaisuus- ja vuodenaikaisuus-kyselylomakkeisiin. Tutkimuksessa IV selvitettiin lisääko kesä- ja talviaikaan siirtyminen maniajaksojen ja tapaturmien määrää. Tutkimusta varten kartoitettiin sairaalassa hoidetut maniajaksot ja tapaturmat kaksi viikkoa ennen kesä- ja talviaikaan siirtymistä ja kaksi viikkoa siirtymien jälkeen vuosina 1987-2003. Tutkimuksessa V kartoitettiin, onko vuorokausirytmin häiriintymisellä yhteyttä Non-Hodgkin-lymfooman esiintyvyyteen. Tutkimusta V varten käytiin läpi syöpärekisterin tiedot vuonna 1970 väestölaskentaan osallistuneiden työikäisten syöpäsairauksista vuosilta 1971-1995. Tutkimuksissa I-III havaittiin kesä- ja talviaikaan siirtymisen häiritsevän sekä uni-valverytmiä että nukkumisen tehokkuutta. Lisäksi havaittiin, että lyhyt uniset ovat pitkä unisia herkempiä vuorokausirytmin muutoksille. Tutkimustulokset viittaavat myös siihen, että vuorokausirytmin muutoksiin sopeutuminen saattaa olla ikä-, sukupuoli- ja kronotyyppi sidonnaista. Tutkimuksessa IV ei havaittu kesä- tai talviaikaan siirtymisen lisäävän merkittävästi sairaalahoitoa vaativien maniajaksojen tai tapaturmien esiintyvyyttä. Tutkimus IV kuitenkin paljasti mielenkiintoisia eroja tapaturmien ja maniajaksojen ilmaantuvuudessa eri vuodenaikojen välillä. Tutkimuksessa V havaittiin, että vuorokausirytmin häiriintymisellä saattaa olla yhteyksiä syövän syntyyn. Non-Hodgkin-lymfooma oli yleisintä yötyötä tekevillä. Väitöskirjatyön osajulkaisut yhdessä osoittavat, että vuorokausirytmin häiriöillä on haitallisia terveysvaikutuksia. Vuorokausirytmin häiriintyminen heikentää unen laatua ja uni-valverytmiä, ja pitkään jatkuessaan voi johtaa syöpäkasvainten kehitykseen. Vuorokausirytmin häiriöt ovat yleisiä ja täten häiriöiden terveysvaikutuksilla on kansanterveydellistä merkitystä. Täten vuorokausirytmin häiriöiden terveysvaikutusten tutkimusta tulee jatkaa parempien ennaltaehkäisy- ja hoitomenetelmien kehittämiseksi. Asiasanat: Vuorokausirytmi, kesäaika, mania-jaksot, tapaturmat, Non-Hodgkin lymfoom

Ramifications of positive and negative contact experiences among remigrants from Russia to Finland

Peer reviewe

Identity and attitudinal reactions to perceptions of intergroup interactions among ethnic migrants: A longitudinal study

Peer reviewe

The dynamics of ethnic discrimination, identities, and outgroup attitudes: A pre-post longitudinal study of ethnic remigrants.

Peer reviewe

National Identification and Intergroup Attitudes Among Members of the National Majority and Immigrants: Preliminary Evidence for the Mediational Role of Psychological Ownership of a Country

In this study, we examined whether psychological ownership of the country one lives in (in this case, Finland) mediates the relationship between national identification and intergroup attitudes among majority and minority group members (N = 647; Finns, n = 334, Russian-speaking immigrants, n = 313). Consistent with our predictions, both majority group members and immigrants whose national identification was strong experienced greater psychological ownership of Finland; as expected, this relationship was more pronounced among majority group members. Higher psychological ownership, in turn, was associated with less positive attitudes towards Russian-speaking immigrants among majority Finns but more positive attitudes towards Finns among immigrants. The findings also showed that among immigrants, the relationship between national identification and psychological ownership is likely to be reciprocal, with national identification similarly mediating the association between psychological ownership and attitudes towards members of the national group. No support for such reciprocity between national identification and psychological ownership was found among members of the majority group.Peer reviewe

Actigraphic Recording of Manic Symptoms Induced by Methylphenidate

Objective. Attention-deficit hyperactivity disorder (ADHD) is a developmental disorder characterized by a long-standing pattern of impulsive behavior, hyperkinesia, and inattention. Psychostimulants, for example, methylphenidate, are the treatment of choice for ADHD both in children, adolescents, and adults. Method. The effect of methylphenidate on sleep structure is not well known. We studied the effect of long-acting methylphenidate on sleep in adult ADHD patients, in a naturalistic treatment setting, using actigraphic and polysomnographic recordings. Results. One of our patients experienced manic episode after starting methylphenidate. A wrist-worn accelerometer recording demonstrated a decrease in the duration and quality of sleep. After discontinuation of methylphenidate treatment, the patient's symptoms subsided and there was no need for hospital admission. Actigraphic recording showed a decrease in the amount and quality of the patient's sleep as triggering factor for the manic symptoms. Conclusions. Disruptions of the sleep-wake cycle are probably important etiologic factors in mood disorders, especially bipolar disorder. The changes in length and quality of sleep described in this case report bear close resemblance to those of patients with a manic episode, although these symptoms were induced by methylphenidate

Consumption of fruits and vegetables and its association with sleep duration among Finnish adult population: a nationwide cross-sectional study

IntroductionSleep and diet are crucial determinants of overall health and wellbeing, with the potential to mutually influence each other. This study examined the association between sleep duration and fruits and vegetables (FV) consumption among Finnish adults.MethodsThe study analyzed data from the National FinHealth 2017 Study involving 5,043 adults aged 18 years and above. Participants reported their habitual sleep duration, and dietary consumption through a validated self-administered questionnaire. Confounders such as demographic, socio-economic factors, and chronotype were considered. A sensitivity analysis, which excluded energy under-reporters, was conducted to validate the findings.ResultsMean dietary consumption was compared across three sleep duration categories (short, normal, long), revealing that short sleepers consumed 37 g/d fewer FV, and long sleepers consumed 73 g/d fewer FV than normal sleepers. Binary logistic regression analyses consistently demonstrated significant negative association between FV consumption and both short and long sleep duration across all models, even when adjusted for a range of covariates. Linear regression analyses revealed a positive but non-significant association between sleep duration and FV consumption that became significant when excluding energy under-reporters, particularly in model 1.DiscussionThis study suggests a consistent pattern where deviation from normal sleep duration was associated with decreased FV consumption, suggesting the need for considering sleep patterns in dietary intervention. The substantial role of accurate energy reporting in explaining these associations is highlighted. Further research, including longitudinal studies, is needed to better understand the mechanisms underlying these associations

Perceived ethnic superiority and immigrants' attitudes towards multiculturalism and the national majority

Peer reviewe

Met expectations and the well-being of ethnic remigrants: A longitudinal study

Peer reviewe

Daylight saving time transitions and hospital treatments due to accidents or manic episodes

<p>Abstract</p> <p>Background</p> <p>Daylight saving time affects millions of people annually but its impacts are still widely unknown. Sleep deprivation and the change of circadian rhythm can trigger mental illness and cause higher accident rates. Transitions into and out of daylight saving time changes the circadian rhythm and may cause sleep deprivation. Thus it seems plausible that the prevalence of accidents and/or manic episodes may be higher after transition into and out of daylight saving time. The aim of this study was to explore the effects of transitions into and out of daylight saving time on the incidence of accidents and manic episodes in the Finnish population during the years of 1987 to 2003.</p> <p>Methods</p> <p>The nationwide data were derived from the Finnish Hospital Discharge Register. From the register we obtained the information about the hospital-treated accidents and manic episodes during two weeks before and two weeks after the transitions in 1987–2003.</p> <p>Results</p> <p>The results were negative, as the transitions into or out of daylight saving time had no significant effect on the incidence of accidents or manic episodes.</p> <p>Conclusion</p> <p>One-hour transitions do not increase the incidence of manic episodes or accidents which require hospital treatment.</p