Riikka Pyhälä
University of Helsinki
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Publication
Featured researches published by Riikka Pyhälä.
The Journal of Clinical Endocrinology and Metabolism | 2010
Katri Räikkönen; Karen A. Matthews; Anu-Katriina Pesonen; Riikka Pyhälä; E. Juulia Paavonen; Kimmo Feldt; Alexander Jones; David I. W. Phillips; Jonathan R. Seckl; Kati Heinonen; Jari Lahti; Niina Komsi; Anna-Liisa Järvenpää; Johan G. Eriksson; Timo E. Strandberg; Eero Kajantie
CONTEXT Neuroendocrine alterations, with well-known links with health, may offer insight into why poor sleep is associated with poor health. Yet, studies testing associations between sleep and neuroendocrine activity in children are scarce. OBJECTIVE The aim of this study was to determine whether actigraphy-based sleep pattern is associated with hypothalamic-pituitary-adrenocortical axis and sympatho-adrenal-medullary system activity in children. DESIGN AND SETTING We conducted a cross-sectional study in a birth cohort in Helsinki, Finland. PARTICIPANTS We studied 282 8-yr-old children. MAIN OUTCOME MEASURES We measured diurnal salivary cortisol and salivary cortisol and alpha-amylase (a sympatho-adrenal-medullary system marker) responses to the Trier Social Stress Test for Children (TSST-C). RESULTS Children with short (<or=7.7 h) vs. average sleep duration (7.8-9.3 h) displayed higher cortisol awakening response and nadir (P < 0.042). Those with low (<or=77.4%) vs. average-high sleep efficiency (>77.4%) displayed higher diurnal cortisol levels across the entire day (P < 0.03), higher cortisol levels after the TSST-C stressor (P < 0.04), and higher overall alpha-amylase levels across the entire TSST-C protocol (P < 0.05). The effects were not confounded by factors that may alter sleep or hormonal patterns. CONCLUSIONS Poor sleep may signal altered neuroendocrine functioning in children. The findings may offer insight into the pathways linking poor sleep with poor health.
The Journal of Pediatrics | 2010
Petteri Hovi; Sture Andersson; Katri Räikkönen; Sonja Strang-Karlsson; Anna-Liisa Järvenpää; Johan G. Eriksson; Anu-Katriina Pesonen; Kati Heinonen; Riikka Pyhälä; Eero Kajantie
OBJECTIVE We hypothesized that, as compared with a matched control group born at term, young adults with very low birth weight (VLBW <1.5 kg) would have higher 24-hour ambulatory blood pressure. STUDY DESIGN We studied 118 18- to 27-year-old subjects born with VLBW within the greater Helsinki area and 120 term-born control subjects with similar age, sex, and birth hospital. The mean birth weight for VLBW subjects was 1.1 kg (standard deviation [SD], 0.2) and for controls, 3.6 kg (SD, 0.5). Gestational ages were 29.2 (SD, 2.3) and 40.1 (SD, 1.0) weeks. Current education of higher-educated parents served as an indicator of childhood socioeconomic status. Ambulatory blood pressure was measured during a 24-hour period with an oscillometric device (Spacelabs 90207). RESULTS VLBW subjects had, with sex, age, and body mass index adjustment, a 2.4 mm Hg (95% confidence interval, 0.2 to 4.6) higher 24-hour systolic pressure. We found hypertension in 11 VLBW subjects and in 3 term-born subjects, giving an adjusted odds ratio of 4.0 (1.1 to 14.8). When socioeconomic status was taken into account, results remained unchanged. CONCLUSIONS Higher rates of hypertension and higher 24-hour blood pressure among young adults with VLBW may indicate higher risk for adverse cardiovascular outcomes.
Neurology | 2011
Riikka Pyhälä; Jari Lahti; Kati Heinonen; A.-K. Pesonen; Sonja Strang-Karlsson; Petteri Hovi; Anna-Liisa Järvenpää; Johan G. Eriksson; Sture Andersson; Eero Kajantie; Katri Räikkönen
Objective: Although severely preterm birth has been associated with impaired neurocognitive abilities in children, follow-up studies in adulthood are scarce. We set out to study whether adults born with very low birth weight (VLBW) (<1,500 g), either small for gestational age (SGA) (birth weight ≤−2 SD) or appropriate for gestational age (AGA), differ in a range of neurocognitive abilities and academic performance from adults born at term and not SGA. Methods: As part of the Helsinki Study of Very Low Birth Weight Adults, 103 VLBW (37 SGA) and 105 term-born control adults (mean age 25.0, range 21.4–29.7 years) without major neurosensory impairments participated in the follow-up study in 2007–2008. The test battery included measures of general cognitive ability as well as executive functioning and related abilities. Academic performance was self-reported. Results: With adjustment for sex and age, the VLBW group scored lower or performed slower than the control group in some indices of all tests (these mean differences ranged from 0.3 to 0.5 SD units, p ≤ 0.03) and they had received remedial education at school more frequently; however, no differences existed in self-reported academic performance. The differences were evident in both VLBW-SGA and VLBW-AGA groups. Further covariate adjustments for parental education, current head circumference, and head circumference at birth and, in tests of executive functioning and related abilities, adjustment for IQ estimate had minor effects on the results. Conclusions: In comparison with control adults, VLBW adults scored lower on several neurocognitive tests. Poorer neurocognitive performance is associated with VLBW irrespective of the intrauterine growth pattern.
Pediatrics | 2009
Riikka Pyhälä; Katri Räikkönen; Kimmo Feldt; Sture Andersson; Petteri Hovi; Johan G. Eriksson; Anna-Liisa Järvenpää; Eero Kajantie
Young adults born prematurely with very low birth weight (≤1500 g) have higher blood pressure than do their counterparts born at term. We tested whether they also have higher blood pressure reactivity to psychosocial stress, which may be a more-specific predictor of long-term cardiovascular morbidity. Systolic and diastolic blood pressure levels for 44 very low birth weight adults (mean age: 23.1 years; SD: 2.3 years) and 37 control subjects (mean age: 23.6 years; SD: 2.0 years) were measured through noninvasive finger photoplethysmography during a standardized psychosocial stress challenge (Trier Social Stress Test). Baseline and task values and their difference (ie, reactivity) served as outcome variables. In comparison with the control group, the very low birth weight group had 7.9 mm Hg higher diastolic blood pressure during the task and 4.8 mm Hg higher diastolic reactivity, with adjustment for gender and age, height, and BMI at testing. A similar trend was seen for systolic blood pressure during the baseline period and the task, but the group differences were not statistically significant. Our results indicate that very low birth weight is associated with elevated blood pressure reactivity to psychosocial stress and, therefore, may increase the risk of cardiovascular morbidity.
The Journal of Pediatrics | 2014
Sara Sammallahti; Riikka Pyhälä; Marius Lahti; Jari Lahti; Anu-Katriina Pesonen; Kati Heinonen; Petteri Hovi; Johan G. Eriksson; Sonja Strang-Karlsson; Sture Andersson; Anna-Liisa Järvenpää; Eero Kajantie; Katri Räikkönen
OBJECTIVES To examine whether faster growth from birth to term (40 postmenstrual weeks) and during the first year thereafter was associated with better neurocognitive abilities in adults born preterm with very low birth weight (VLBW; <1500 g). STUDY DESIGN Weight, length, and head circumference data of 103 VLBW participants of the Helsinki Study of Very Low Birth Weight Adults were collected from records. Measures at term and at 12 months of corrected age were interpolated. The participants underwent tests of general neurocognitive ability, executive functioning, attention, and visual memory at mean age of 25.0 years. RESULTS Faster growth from birth to term was associated with better general neurocognitive abilities, executive functioning, and visual memory in young adulthood. Effect sizes in SD units ranged from 0.23-0.43 per each SD faster growth in weight, length, or head circumference (95% CI 0.003-0.64; P values <.05). After controlling for neonatal complications, faster growth in head circumference remained more clearly associated with neurocognitive abilities than weight or length did. Growth during the first year after term was not consistently associated with neurocognitive abilities. CONCLUSIONS Within a VLBW group with high variability in early growth, faster growth from birth to term is associated with better neurocognitive abilities in young adulthood. Neurocognitive outcomes were predicted, in particular, by early postnatal head growth.
Psychoneuroendocrinology | 2012
Anu-Katriina Pesonen; Eero Kajantie; Kati Heinonen; Riikka Pyhälä; Jari Lahti; Alexander Jones; Karen A. Matthews; Johan G. Eriksson; Timo E. Strandberg; Katri Räikkönen
STUDY OBJECTIVES Sleep problems are associated with reduced physical and mental health. Altered function of the hypothalamic-pituitary-adrenocortical axis (HPAA) may be one underlying mechanism. We studied the associations between sleep problems and HPAA activity in children. DESIGN A cross-sectional epidemiological cohort study. SETTING Salivary cortisol was sampled throughout one day at home and during the Trier Social Stress Test for Children (TSST-C) in clinic. Sleep disorders were measured with a parent-rated Sleep Disturbance Scale for Children, and sleep duration measured by actigraphy for one week. PARTICIPANTS 284 (51% girls) 8-year-old children. RESULTS Boys with sleep problems (≥ 85 th percentile in any of the sleep-wake transition, arousal, excessive daytime somnolence or sleep hyperhydrosis subscales) had lower diurnal salivary cortisol levels and salivary cortisol responses to TSST-C stress in comparison to boys without sleep problems. Girls with sleep problems (≥ 85 th percentile in disorders of initiating and maintaining sleep) displayed a higher overall level of salivary cortisol during the TSST-C. Salivary cortisol responses to stress were lower in boys and higher in girls with more than one sleep problem. CONCLUSIONS Sleep problems in children are associated with altered HPAA function, after controlling for actual sleep quantity measured by actigraphy. Boys with sleep problems had lower HPAA activity and girls with sleep problems had higher HPAA activity, compared to children without sleep problems.
Hypertension | 2011
Silja Martikainen; Anu-Katriina Pesonen; Kimmo Feldt; Alexander Jones; Jari Lahti; Riikka Pyhälä; Kati Heinonen; Eero Kajantie; Johan G. Eriksson; Katri Räikkönen
We investigated whether sleep quantity and quality were related to 24-hour ambulatory blood pressure and cardiovascular reactivity in children. We studied term-born, healthy 8.0-year olds (SD: 1.4 years) without sleep-disordered breathing (231 and 265 children provided valid data for analyses of ambulatory blood pressure and cardiovascular reactivity, respectively). Sleep was registered with an actigraph for 6 nights on average (SD: 1.2; range: 3 to 13 nights). Ambulatory blood pressure was measured for 24-hours (41% nonschool days) with an oscillometric device. The children underwent the Trier Social Stress Test for Children, during which blood pressure, electrocardiography, and thoracic impedance were recorded and processed offline to give measures of cardiovascular and autonomic function. Neither quantity nor quality of sleep was related to 24-hour ambulatory blood pressure or cardiovascular reactivity after accounting for major covariates (sex, age, height, body mass index, and parental education). Although lower sympathetic nervous system activation and higher cardiac activation under stress were found in the group of children who slept for short duration when they were compared with the average sleep duration group, these associations were not significant after correction for multiple testing and were not seen in linear regression models of the effects of sleep duration. These findings do not support the mainstream of epidemiological findings, derived from samples more heterogeneous in age, sociodemographic characteristics, and health, suggesting that poor sleep is associated with an unhealthy cardiovascular phenotype.
The Journal of Clinical Endocrinology and Metabolism | 2013
Silja Martikainen; Anu-Katriina Pesonen; Jari Lahti; Kati Heinonen; Kimmo Feldt; Riikka Pyhälä; Tuija Tammelin; Eero Kajantie; Johan G. Eriksson; Timo E. Strandberg; Katri Räikkönen
CONTEXT Children who undertake more physical activity (PA) not only have more optimal physical health but also enjoy better mental health. However, the pathways by which PA affects well-being remain unclear. OBJECTIVE To address this question, we examined whether objectively measured daytime PA was associated with diurnal hypothalamic-pituitary-adrenocortical axis (HPAA) activity and HPAA responses to psychosocial stress. DESIGN AND SETTING We conducted a cross-sectional study in a birth cohort in Helsinki, Finland. PARTICIPANTS We studied 258 8-year-old children. MAIN OUTCOME MEASURES PA was assessed with wrist-worn accelerometers. Overall PA and percentage of time spent in vigorous PA (VPA) were categorized by sex into thirds. Salivary cortisol was measured diurnally and in response to the Trier Social Stress Test for Children. RESULTS The children in different PA groups did not show differences in diurnal salivary cortisol (P > .10 for overall PA and VPA). Children with the highest levels of overall PA or VPA showed no, or only small, increases over time in salivary cortisol after stress (P = .10 and P =.03 for time in analyses of PA and VPA, respectively), whereas children belonging to the lowest and intermediate thirds showed significant increases over time in salivary cortisol after stress (P ≤ .002 for time in the analyses of overall PA and VPA). CONCLUSIONS These results suggest that children with lower levels of daytime PA have higher HPAA activity in response to stress. These findings may offer insight into the pathways of PA on physical and mental well-being.
PLOS ONE | 2013
Katri Räikkönen; Eero Kajantie; Anu-Katriina Pesonen; Kati Heinonen; Hanna Alastalo; Jukka T. Leskinen; Kai Nyman; Markus Henriksson; Jari Lahti; Marius Lahti; Riikka Pyhälä; Soile Tuovinen; Clive Osmond; D. J. P. Barker; Johan G. Eriksson
Objectives To examine whether the adverse effects of slow prenatal and postnatal growth on cognitive function persist to old age and predict age related cognitive decline. Design and Setting A longitudinal birth cohort study of men born in Helsinki, Finland 1934-44. Participants Nine-hundred-thirty-one men of the Helsinki Birth Cohort Study, with detailed data on growth from birth to adulthood, aged 20.1 (SD = 1.4) at the first and 67.9 (SD = 2.5) years at the second cognitive testing. Main Outcome Measures The Finnish Defense Forces Basic Intellectual Ability Test assessed twice over nearly five decades apart. Results Lower weight, length and head circumference at birth were associated with lower cognitive ability at 67.9 years (1.04–1.55 points lower ability per each standard deviation [SD] unit decrease in body size, 95% Confidence Interval [95%CI]: 0.05 to 2.72) and with cognitive decline after 20.1 years (0.07–0.11 SD decline over time per each SD decrease in body size, 95%CI:0.00 to 0.19). Men who were born larger were more likely to perform better in the cognitive ability test over time (1.22–1.43 increase in odds to remain in the top relative to the lower two thirds in ability over time per each SD increase in body size, 95%CI:1.04 to 1.79) and were more resilient to cognitive decline after 20.1 years (0.69 to 0.76 decrease in odds to decline from than remain in the top third of ability over time per each SD increase in body size, 95%CI:0.49 to 0.99). Slower growth between birth and two years in weight, height and body mass index was associated with lower cognitive ability at 67.9 years, but not with cognitive decline. Conclusions Poorer lifetime cognitive ability is predicted by slower growth before and after birth. In predicting resilience to age related cognitive decline, the period before birth seems to be more critical.
Pediatrics | 2014
Riikka Pyhälä; Petteri Hovi; Marius Lahti; Sara Sammallahti; Jari Lahti; Kati Heinonen; Anu-Katriina Pesonen; Sonja Strang-Karlsson; Johan G. Eriksson; Sture Andersson; Anna-Liisa Järvenpää; Eero Kajantie; Katri Räikkönen
OBJECTIVES: We examined whether adults born preterm at very low birth weight (VLBW; <1500 g) differ from term-born adults in autism-spectrum traits, and whether among VLBW adults, growth in infancy is associated with these traits. METHODS: A total of 110 VLBW and 104 term-born adults of the Helsinki Study of Very Low Birth Weight Adults completed the Autism-Spectrum Quotient yielding total, social interaction, and attention to detail sum scores. Growth in weight, length, and head circumference from birth to term and from term to 1 year of corrected age was determined as standardized residuals reflecting growth conditional on previous history. RESULTS: VLBW adults scored higher than term-born controls on social interaction sum score, indicating higher autism-spectrum traits. In contrast, they scored lower on attention to detail sum score, indicating lower autism-spectrum traits. Within the VLBW group, faster growth in weight, length, and head circumference from birth to term was associated with lower total and social interaction sum scores. In this group, growth from term to 1 year was not associated with autism-spectrum traits. CONCLUSIONS: Among those born preterm at VLBW, the risk for higher levels of autism-spectrum traits, particularly related to social interaction, may persist into adulthood. Faster growth from birth to term may ameliorate these effects, suggesting that targeted interventions could aid long-term neurodevelopment.