Seasonal variation in weight-for-age in a pediatric emergency room.

OBJECTIVE. The authors assess seasonal variations in the prevalence of low weight-for-age among young children visiting the pediatric emergency room of a city hospital. METHODS. We analyzed data on 11,118 children ages 6 to 24 months who visited the Boston City Hospital Pediatric Emergency Department between July 1989 and June 1992. Medical diagnoses were documented on a randomly selected subsample of 1,569 children. In addition, a questionnaire about food insecurity was administered to a convenience subsample of 269 families with children under 3 years of age. RESULTS. The percentage of children visiting the emergency room with weight-for-age below the fifth percentile was significantly higher for the three months following the coldest months than for the remaining months of the year, controlling for year of measurement. In the subsample, gastrointestinal illness was correlated with both season of measurement and weight-for-age, but the seasonal effect remained for the entire sample after controlling for dehydration. The questionnaire data suggested a relationship between economic stress and food insecurity that might help explain the seasonal effect. Families who were without heat or who were threatened with utility turnoff in the previous winter were twice as likely as other families to report that their children were hungry or at risk for hunger. CONCLUSIONS. Winter and early spring constituted periods of increased nutritional risk in the in this sample of predominantly low-income children, probably because of the increased caloric associated with cold stress and infections. Further research is needed to assess whether decreased caloric availability due to high heating costs, a "heat or eat" effect, also contributes to this phenomenon.     

Results of nutritional status surveillance in El Salvador, 1975 - 77

Nutritional status surveillance data based on the clinical diagnosis of malnutrition and on weight-for-age, as well as diarrhoeal disease data for preschool age children attending government health clinics in El Salvador are presented for a 3-year period (1975 - 77). Surveillance results indicated consistently higher rates of clinical malnutrition and weight-for-age deficit in rural children as compared with urban children, and higher malnutrition rates in children 1 - 4 years of age as compared with infants less than 1 year old. Consistent seasonal increases in malnutrition were observed that were most pronounced in older preschool children (1 - 4 years) in rural areas. Seasonal peaks in malnutrition consistently followed 1 - 2 months after the major seasonal peak in diarrhoea at the onset of the rainy season, suggesting that diarrhoea may play a role in the etiology of malnutrition. A secondary seasonal peak in diarrhoea in the cooler, dry season was most prominent in infants but was not related to increased malnutrition. These results indicate that nutritional and health status indicators formed from data collected regularly at health centres can demonstrate consistent age group, urban/rural, and seasonal differences in nutritional status that may be useful in identifying risk groups and in monitoring nutritional changes for planning and evaluation purposes.     

Swiss pilot study of individual seasonal fluctuations of urinary iodine concentration over two years: is age-dependency linked to the major source of dietary iodine?

OBJECTIVE: Because of known significant seasonal fluctuations of iodine concentration in cow's milk (ICM) in Switzerland (winter/summer (w/s) ICM ratio averages 5.6), we looked for seasonal variations and familial aspects in urinary iodine and sodium concentrations (UIC, UNaC). DESIGN:: Prospective sequential cohort investigation. SETTING: University hospital. SUBJECTS: Thirteen children (six girls, seven boys) aged 3-10 y and their parents (n=9) aged 30-47 y. INTERVENTIONS: The volunteers collected 1729 spot urine samples (5.1996-5.1998). UIC data from winter (UIC(w): December-February) and summer seasons (UIC(s): July-September) were compared with UNaC and average milk consumption. Iodine intakes from milk and salt were modelized. RESULTS: Highest seasonal fluctuations of UIC were found in six pre-school children (w/s UIC group average=1.56, significant), followed by seven school children (w/s UIC group average=1.24, N.S.); none existed in adults. UIC/UNaC showed corresponding seasonal fluctuations in children, but not in adults. Winter milk was an important iodine source for children, as proven indirectly by similar seasonal fluctuations of ICM, UIC, UIC/UNaC and an important part within UIC due to milk. CONCLUSIONS: Contribution to UIC from milk intake during winter was high in children (40-50%) and lower in adults (about 20%). Compared with children, dietary habits of adults are more complex and their iodine supply depends mainly on iodized salt and not on milk, so the effect of seasonal ICM variations on UIC is less marked. Because of significant seasonal UIC fluctuations in consumers of fresh milk products in Switzerland, results of future UIC studies conducted during summer and winter seasons should be compared cautiously, especially in young children. Furthermore, consumption of milk is to be promoted, since, besides calcium and vitamins, it is an essential source of iodine. UNaC determination should be included in epidemiologic studies if the dietary source of iodine is questioned.     

Components of 25-hydroxyvitamin D in serum of young children in upper midwestern United States.

The relative importance of cholecalciferof (vitamin D3) and ergocalciferol (vitamin D2) in maintaining the vitamin D level in children (1/2 to 6 years old) living in the upper midwestern United States was determined by measurement of total 25-hydroxyvitamin D (25-OH-D), its components, and other indices of calcium homeostasis in serum. In 38 normal children, mean (range) serum total 25-OH-D was 32.8 (less than 5 to 53) ng/ml; in 25 of the 28 sera partitioned, the major component was 25-OH-D3. Significant seasonal variation in serum 25-OH-D3 (mean, range: 35.2, 17 to 51 ng/ml in summer and 15.9, less than 5 to 32 ng/ml in winter) was not accompanied by changes in mean serum 25-OH-D2, calcium, phosphorus, or alkaline phosphatase values. However, individual serum total 25-OH-D values correlated with serum phosphorus values (r = 0.37; P less than 0.05). The proportion of the total represented by 25-OH-D3 varied widely, with a a mean of 83% in summer and 67% in winter. Sources of D3, which include both dermal synthesis and intestinal absorption of D3 added to milk, appear to be more important than sources of D2 in maintaining vitamin D nutrition of young children throughout the year. However, sources of D2 offset the decrease in total 25-OH-D in winter months.     

Seasonal diarrhoeal mortality among Mexican children.

The study investigated the effects on diarrhoeal deaths among under-5-year-old Mexican children of the following variables: season (summer or winter), region (north versus south), age group, and place of death. Examination of death certificates indicated that the distribution of deaths in 1989-90 was bimodal, with one peak during the winter and a more pronounced one during the summer. In 1993-94, however, the winter peak was higher than that in the summer (odds ratio (OR) = 2.04). These findings were due mostly to deaths among children aged 1-23 months (OR = 1.86). Diarrhoeal mortality was highest among children aged 6-11 months (OR = 2.23). During the winter, there was a significant increase in the number of deaths that occurred in medical care units and among children who had been seen by a physician before they died, but deaths occurring at home showed no seasonal variation. In the northern states, the reduction in diarrhoeal mortality was less in winter than in summer (OR = 2.62). In the southern states, the proportional reduction during the winter was similar to that in the summer.     

The Impact of COVID-19 Pandemic during 2020–2021 on the Vitamin D Serum Levels in the Paediatric Population in Warsaw,Poland

Background: The main source of vitamin D is skin synthesis, which depends on sunlight exposure. During the pandemic, COVID-19 children were obliged to home confinement, which potentially limiting sunlight exposure. The aim of this study was to evaluate whether home confinement led to decreased vitamin D serum levels in children in Warsaw, Poland. Methods: The study included 1472 children who were divided into two groups, based on the date of 25(OH)D level blood sampling: before and during the pandemic. Children under 1 year of age (infants) were analysed separately. Results: A statistically significant decrease in the average level of vitamin D was observed between groups of children over 1 year of age (35 ng/mL ± 18 vs. 31 ng/mL ± 14). In infants from both groups, the mean vitamin D levels were within the normal range (Group 1 inf 54 ng/mL ± 21 vs. Group 2 inf 47 ng/mL ± 15). The characteristic seasonal variability was observed before the pandemic, with maximal vitamin D levels in summer (40 ng/mL ± 17) and minimal levels in winter (30 ng/mL ± 14). During the pandemic, no seasonal variability was observed (summer 30 ng/mL ± 11 vs. winter 30 ng/mL ± 19). Conclusions: The COVID-19 pandemic restrictions led to a significant decrease in vitamin D serum levels in children.     

Seasonal variation in bone lead contribution to blood lead during pregnancy

Population blood lead level (PbB) often shows seasonal variation, frequently being higher in summer and lower in winter. As vitamin D metabolites also show seasonal variability, and the metabolites are associated with bone metabolism, some authors have posited a role for bone lead release in seasonal PbB changes. We made third trimester and postdelivery PbB measurements on 414 immigrant women (98% Latina) in Los Angeles. We measured in vivo tibia and calcaneus (heel) lead concentration postdelivery via K-shell X-ray fluorescence. We saw evidence of seasonal variation in prenatal PbB, but not postnatal PbB. PbB was highest in spring and lowest in autumn. Tibia lead concentration was associated with prenatal PbB, as reported before. The contribution of tibia lead to prenatal PbB varied seasonally, with the greatest contribution occurring in the winter quarter and the least in the summer quarter. The temporal pattern of bone lead contribution to PbB follows the seasonal alteration of insolation. There was no seasonal component in prenatal PbB associated with calcaneus lead, nor were there seasonal variations in either calcaneus or tibia lead contributions to postnatal PbB. Bone turnover in the third trimester of pregnancy may be higher in winter months than in summer months, resulting in greater fetal lead exposure in spring than at other times of the year.     

Comparing physical activity questionnaires for youth: seasonal vs annual format

BACKGROUND: In large cohort studies of older children, self-report is the only practical way to assess physical activity. Assessing usual activity over the entire year is desirable, but children and adolescents may overestimate activities with high seasonal variability. Use of questionnaires in which individuals report each activity by season may improve accuracy. METHODS: A total of 6782 girls and 5110 boys, aged 9-14 years in 1996, completed self-administered activity questionnaires in 1996 and in 1997. In 1996, participants reported the average time spent in each of 17 activities during the previous 12 months; in 1997, we also asked for the average time spent in the previous year, but within each of the four seasons. RESULTS: Girls reported a median of 12.8 hours/week total activity in 1996 and 10.4 hours/week in 1997. For boys, the estimates were 15.5 hours/week and 13.4 hours/week, respectively. Girls and boys within 1-year age strata (e.g., comparison of 10-year olds in 1996 with 10-year olds in 1997) reported an average of 3.7 and 3.1 fewer hours per week, respectively, on the 1997 seasonal format versus the 1996 annual format questionnaire. In longitudinal analyses, the difference between the annual and the seasonal estimates was greater if participants did the activity in fewer seasons in 1997. CONCLUSIONS: In comparison to an annual format questionnaire, a seasonal format questionnaire may improve accuracy of self-report of physical activity by reducing over-reporting of activities in which pre-adolescents and adolescents engage in fewer seasons.     

Season Modifies the Relationship between Bone and Blood Lead Levels: The Normative Aging Study

Bone serves as a repository for 75% and 90–95% of lead in children and adults, respectively. Bone lead mobilization heightens during times of increased bone turnover, such as pregnancy, lactation, hyperthyroidism, and the rapid growth of childhood. Blood lead levels show seasonal periodicity. Children demonstrate peak blood lead levels in midsummer and a secondary peak in late winter. Pregnant women demonstrate the highest mean blood lead levels in winter (January-March) and the lowest in summer (July-September). This fluctuation in blood lead levels may be related to seasonal patterns of environmental exposures, but it may also be partially related to the increased mobilization of bone lead stores during the winter months. We performed bone lead measurements using a K-x-ray fluorescent instrument to determine micrograms of lead per gram of bone mineral (parts per million) in middle-aged and elderly men who participated in the Normative Aging Study. We obtained measurements of blood and bone lead during the high sun exposure months of May-August (summer; n = 290); the intermediate sun exposure months of March, April, September, and October (spring/fall; n = 283); and the low sun exposure months of November-February (winter; n = 191). Mean blood lead concentrations were 5.8 μg/dl, 6.1 μg/dl, and 6.6 μg/dl for the summer, spring/fall, and winter, respectively. Mean patella (trabecular bone) lead concentrations were 34.3 μg/gm, 29.7 μ/gm, and 29.0 μg/gm for the summer, spring/fall, and winter time periods, respectively. In multivariate regression models, adjusted for age, smoking, alcohol ingestion, and dietary intake of iron and vitamin C, the authors found a strong interaction between season and bone lead level—with bone lead levels exerting an almost 2-fold greater influence on blood levels during the winter months than the summer months. The authors concluded that elevated blood lead levels in winter may be related to increased mobilization of endogenous bone lead stores, potentially from decreased exposure to sunlight, lower levels of activated vitamin D, and enhanced bone resorption.     

Delayed onset and diminished magnitude of rotavirus activity--United States, November 2007-May 2008

Rotavirus is the leading cause of severe acute gastroenteritis among infants and young children, accounting for an estimated 527,000 deaths among children aged <5 years worldwide in 2004 (1,2). In the United States, rotavirus causes few deaths (20-60) each year, but remains a substantial cause of morbidity among children, resulting in approximately 55,000--70,000 hospitalizations, 205,000-272,000 emergency department (ED) visits, and 410,000 physician office visits. In the continental United States, rotavirus activity follows a distinct winter-spring seasonal pattern. In winter months, approximately 50% of hospitalizations and ED visits and 30% of outpatient visits for acute gastroenteritis among U.S. children aged <3 years are caused by rotavirus. To prevent rotavirus disease, in February 2006, a human-bovine rotavirus vaccine, RotaTeq (Merck & Co., Inc., Whitehouse Station, New Jersey), was recommended for routine use among U.S. infants . To summarize rotavirus activity through May 3, during the current 2007-08 season, CDC analyzed data from the National Respiratory and Enteric Virus Surveillance System (NREVSS) and the New Vaccine Surveillance Network (NVSN). The results indicated that, when compared with the 15 previous seasons spanning 1991-2006, rotavirus activity during the current season appeared delayed in onset by 2-4 months and diminished in magnitude by >50%. Additional surveillance and epidemiologic studies are needed to confirm the impact of rotavirus vaccination on the 2007-08 season and to monitor the impact of the vaccine on the incidence and epidemiology of rotavirus during future seasons.     

The effect of ascorbic acid on the seasonal variations in serum cholesterol levels

One gram of ascorbic acid (Vitamin C) administered randomly to a group of healthy young people (aged 29 +/- 5 years) produced a significant mean fall in serum cholesterol of 16 per cent within two months. A similar supplement to a group of healthy older people (aged 58 +/- 3 years) produced a significant mean fall in serum cholesterol of 14 per cent but required six to 12 months' administration. Serial observations on a mixed age group of healthy people (aged 38 +/- 12 years) over one calendar year revealed a seasonal fluctuation in serum cholesterol, the lowest levels being in summer (June 5.5 +/- 0.7 mmols/l) and the highest levels in winter (January 6.4 +/- 0.8 mmols/l), a significant rise of 16 per cent. These changes showed an inverse relationship with the leucocyte and serum ascorbic acid levels which also revealed a seasonal fluctuation, the months April/September being higher than the months October/March. The administration of 1g of ascorbic acid per day throughout the year abolished the winter rise in serum cholesterol levels. These results are discussed in the light of the relationship between cholesterol and vascular disease and the observations by Sir Richard Doll that lowering the cholesterol level, whether achieved by drugs or diet, results in a reduction in morbidity from myocardial infarction.     

Elevated blood lead concentrations and vitamin D deficiency in winter and summer in young urban children

BACKGROUND: It is widely recognized that blood lead concentrations are higher in the summer than in winter. Although the effects of some environmental factors such as lead in dust on this phenomenon have been studied, relationships to sunlight-induced vitamin D synthesis have not been adequately investigated. Vitamin D status is influenced by the diet, sunlight exposure, age, skin pigmentation, and other factors, and may modify gastrointestinal lead absorption or release of lead stored in bones into the bloodstream. OBJECTIVE AND METHODS: We collected paired blood samples from 142 young, urban African-American and Hispanic children in the winter and summer to study the seasonal increase in blood lead and its relationships to vitamin D nutrition, age, and race. RESULTS: A winter/summer (W/S) increase in blood lead concentrations of 32.4% was found for children 1-3 years of age. There was a smaller W/S increase of 13.0% in children 4-8 years of age. None of the 51 Hispanic children had an elevated blood lead concentration (> or = 10 microg/dL) during the winter, and only one had an elevated summertime concentration. In contrast, elevated blood lead concentrations were frequent in the 91 African-American children, especially those 1-3 years of age. For the latter, the percentage with elevated blood lead levels increased from 12.2% in winter to 22.5% in summer. A 1.2% W/S increase in serum 25-hydroxy-vitamin D (serum 25-OH-D) concentrations was found for children 1-3 years of age. However, in children 4-8 years of age the W/S increase in serum 25-OH-D was much larger-33.6%. The percentages of children with low (< 16 microg/L) serum 25-OH-D concentrations were 12.0% in winter and 0.7% in summer and were consistently greater in African-American than in Hispanic children. The seasonal increases in blood lead and serum 25-OH-D in children 4-8 years of age were significantly associated. CONCLUSION: The higher summertime serum 25-OH-D concentrations for the 4- to 8-year-old children are likely caused by increased sunlight-induced vitamin D synthesis and may contribute to the seasonal increase in blood lead. Age and race are key factors that affect blood lead and vitamin D nutrition, as well as their interactions, in young urban children.     

Children born in the summer have increased risk for coeliac disease

STUDY OBJECTIVE: Coeliac disease, also called permanent gluten sensitive enteropathy, is being recognised as a widespread health problem. Defining the possible role of environmental factors in its aetiology might open doors to primary prevention. This study therefore analysed if the risk for coeliac disease varies with month of birth as a proxy for a seasonal pattern for possible causal environmental exposure(s). DESIGN: A population based incidence register of coeliac disease in children below 15 years of age covering the period from 1973 to 1997. Incidence rates were calculated by month of birth, stratified for age at diagnosis. Poisson regression analyses were used to estimate the relative risk for coeliac disease for children below 2 years of age by season of birth, also taking into account gender and time period of diagnosis. SETTING: Sweden. PARTICIPANTS: All 2151 children in the study base with verified coeliac disease. MAIN RESULTS: The risk for coeliac disease was significantly higher if born during the summer as compared with the winter (RR=1.4, 95% CI 1.2 to 1.7), but only in children below 2 years of age at diagnosis. This relative seasonal risk pattern prevailed during a 10 year epidemic of coeliac disease, although incidence rates varied threefold. The incidence was constantly higher among girls as compared with boys, but boys showed a more pronounced seasonal variation in risk than girls. CONCLUSIONS: An increased coeliac disease risk in children born in the summer compared with the winter reflects causal environmental exposure(s) with a seasonal pattern. Infections might be the exposure of importance, either by means of a direct causal role and/or through interaction with other exposures, for example, gluten intake. However, non-infectious exposures should also be explored as possible contributing causal factors.     

The risk factors and quality of life in children with allergic rhinitis in relation to seasonal attack patterns

A questionnaire survey was conducted to examine whether risk factors and allergic rhinitis (AR)-related quality of life (QOL) were different among children with different seasonal patterns of AR. Participants were students enrolled in elementary and middle schools in Taipei County, Taiwan. Using moving average and principal component analysis, children with current AR were grouped by attack seasons. The effects of personal and environmental factors on AR seasonality were assessed by logistic regression models. AR severity and AR-related QOL were compared within AR seasonal subtypes. Among 4221 children who completed the questionnaire, 1144 and 1605 children were current AR cases and healthy controls, respectively. Four AR subtypes were categorised as follows: perennial, spring, summer/fall, and winter. Age, gender, parental education, maternal passive smoking during pregnancy, breast feeding, and mouldy walls were found to contribute differentially to different AR subtypes. Children suffering from perennial and winter AR were found to have more severe symptoms and significantly lower QOL score compared with other subtypes. Specific personal and environmental risk factors could contribute to different AR seasonal subtypes. Active allergen avoidance and symptomatic treatment should be the focus of management aiming to improve the QOL among children with perennial and winter subtype.     

Seasonality of growth in Shanghai infants (n=4128) born in 11 consecutive years

OBJECTIVE: To describe the seasonal growth patterns in Shanghai infants, to explore seasonal time lag between weight gain and length gain, and to investigate the long-term effect of birth season on early postnatal growth. DESIGN: Community-based longitudinal study. SETTING: Shanghai, People's Republic of China. METHOD: Children were followed up monthly from 1 to 6 months, 3 monthly from 6 to 12 months, and 6 monthly from 12 to 24 months. SUBJECTS: A total of 6018 children born between 1 January 1980 and 31 December 1990. MAIN OUTCOME MEASURES: Weight gain, length gain and change in body mass index (BMI) over the seasons of the year. RESULTS: The infants tended to grow faster in height in spring and summer, and faster in weight and BMI in autumn and winter. The seasonal effect on weight gain and length gain is largely independent. The mean length value at 1 month of age was about 2.0 cm higher in infants born in May to July than in those born in November to February. At 24 months of age this difference was reduced to about 0.7 cm. CONCLUSIONS: There is a clear and consistent seasonality in growth in Shanghai infants. The seasonality seems to act independently on weight and length. Birth month has some association with attained size, but this is reduced during the first 2 y of life.     

Seasonal variation in coronary heart disease in Scotland.

STUDY OBJECTIVE--Seasonality of coronary heart disease (CHD) was examined to determine whether fatal and non-fatal disease have the same annual rhythm. DESIGN--Time series analysis was carried out on retrospective data over a 10 year period and analysed by age groups ( < 45 to > 75 years) and gender. SETTING--Data by month were obtained for the years 1962-71. The Registrar General provided information on deaths and the Research and Intelligence Unit of the Scottish Home and Health Department on hospital admissions. SUBJECTS--In Scotland, between 1962 and 1971, 123 000 patients were admitted to hospital for CHD, of whom 29 000 died. There were a further 97 000 CHD deaths outside hospital. These two groups were also examined as one (coronary incidence) - that is, all coronary deaths and coronary admissions discharged alive. STATISTICAL ANALYSIS AND MAIN RESULTS: Where there was a single annual peak, the sine curve was analysed by cosinor analysis. When there were two peaks the analysis was by normal approximation to Poisson distribution. In younger men (under 45 years) admitted to hospital there was a dominant spring peak and an autumn trough. A bimodal pattern of spring and winter peaks was evident for hospital admissions in older male age groups: with increasing age the spring peak diminished and the winter peak increased. In contrast, female hospital admissions showed a dominant winter/summer pattern of seasonal variation. In male and female CHD deaths seasonal variation showed a dominant pattern of winter peaks and summer troughs, with the winter peak spreading into spring in the two youngest male age groups. CHD incidence in women showed a winter/summer rhythm, but in men the spring peak was dominant up to the age of 55. CONCLUSION--The male, age related spring peak in CHD hospital admissions suggests there is an androgenic risk factor for myocardial infarction operating through an unknown effector mechanism. As age advances and reproduction becomes less important, the well defined winter/summer pattern of seasonal variation of CHD is superimposed, and shows a close relationship with the environment, especially temperature, or the autumn and early winter fall in temperature.     

儿童急性呼吸道感染病毒病原检测741例分析

目的了解当前沧州地区儿童急性呼吸道病毒感染(acute respiratory infection,ARI)病原学的状况,为临床儿童急性呼吸道感染提供病毒病原学诊断依据。方法选择2012年5月-2013年7月于河北省沧州市中心医院确诊的ARI住院患儿共74l例,取其鼻咽分泌物采用直接免疫荧光法检测7种病毒即呼吸道合胞病毒(RSV)、腺病毒(ADV)、副流感病毒Ⅰ、Ⅱ、Ⅲ((PIV 1、PIV 2、PIV 3)、流感病毒A、B(IFV A、IFV B)。结果 741例患儿中阳性212例,总阳性率28.6%。不同性别患儿间阳性率比较差异无统计学意义(P=0.753)。RSV是住院ARI患儿最主要病原,其次是PIV3;冬季病毒阳性检出率最高,为45%,秋季最低,为15%。年龄≤3岁组检测阳性率明显高于4~7岁组和≥8岁组,差异均有统计学意义。结论 RSV是导致沧州地区儿童呼吸道感染的主要病原体;病毒感染流行性有明显的季节特征,冬春季高发;不同年龄儿童对各种病毒存在不同的易感性。     

The effect of massive doses of vitamin A on the signs of vitamin A deficiency in preschool children.

Marked seasonal variation in the prevalence of signs of vitamin A deficiency was found in the 2nd year of a continuing study of children age 0 to 4-1/2 years in a village in West Bengal, confirming results of a previous 18-month study. Administration of 200,000 IU of vitamin A every 4 months completely eliminated night blindness and prevented the development of new cases of Bitot's spot in a statistically significant number of children. The effectiveness of massive doses of vitamin A, administered at intervals of 4 months, as a short-term measure to fight the problem, was confirmed in this village. The study yielded additional evidence of the complex etiology of Bitot's spot, since alternate day dose of vitamin A in addition to massive therapy failed to eliminate these spots.     

The effects of seasonal variations and weather conditions on the occurrence of heart attacks in Hungary between 2000-2004

INTRODUCTION: The onset of acute myocardial infarct shows circadian and seasonal variations, that are influenced by sex, age and the changes of weather conditions as well. AIM: The purpose of our present study is to investigate whether a seasonal variation can be found in the onset of myocardial infarctions during the period under investigation, and whether certain meteorological factors (air temperature, atmospheric pressure, front movements) influence the incidence of myocardial infarction. METHODS: Retrospective analysis has been carried out on patients admitted because of acute myocardial infarct in Hungary between 2000 and 2004 ( n=81.956). Data have been taken from the database of the National Health Insurance Fund Administration based on the International Classification of Diseases (ICD). Weather related data were provided by the National Meteorology Service. RESULTS: Regarding seasonal distribution the peak incidence period of acute myocardial infarct was spring, whereas the lowest number of events was observed during the summer months. There was a marked difference in the number of events per season ( p<0.001). A medium level negative correlation was found between the monthly average temperature and the occurrence of heart attack ( r=-0.404) during the period examined. A positive correlation was shown between front movements and the of number of events per season ( r=0.053). CONCLUSION: Our findings show that certain meteorological factors may be related to the onset of acute myocardial infarct, however, a number of other factors may also play an important role.     

Seasonal and climatic variation in cholesterol and vitamin C: effect of vitamin C supplementation.

Vitamin C (ascorbic acid) is an important anti-oxidant which may help to reduce free radical damage and atheroma formation in blood vessels. In a study in which a group of healthy volunteer subjects were followed up for 12 months and a group of patients with vascular disease taking Vitamin C supplements were followed for 23 months, we confirmed previous findings of seasonal variations in ascorbic acid and cholesterol and have shown an inverse relationship between leucocyte ascorbic acid and serum cholesterol levels. In healthy control subjects the increase in ascorbate and fall in cholesterol during the summer months was reversed when the weather changed to a more winter pattern, presumably due to dietary alterations. We found that ascorbic acid levels were lower in patients with peripheral vascular disease and that although normal ascorbic acid levels were achieved with Vitamin C supplementation, when supplements were stopped at the height of a normal summer, there was a fall in ascorbic acid and a rise in serum cholesterol to winter levels. Given these findings we suggest that patients with vascular disease should have Vitamin C supplements throughout the year.