Seasonal Variation In Diagnosis Research Articles

Seasonal variation in diagnosis of cutaneous invasive melanoma and cutaneous squamous cell carcinoma: A nationwide study in the Netherlands

BackgroundCurrently, there is no study that has reported on the seasonal trends of skin cancer in the Netherlands. This study aimed to investigate seasonal variation in diagnosis of cutaneous melanoma (CM) and cutaneous squamous cell carcinoma (cSCC) focusing on different subgroups. MethodsCM diagnosed from 2001 till 2019 and cSCCs from 2001 till 2015 were selected from the Netherlands Cancer Registry. The monthly distribution of CM and cSCC diagnoses were evaluated. Summer-to-winter ratios (SWRs) were calculated overall and stratified by patient and tumour characteristics. ResultsSignificant increases in melanoma incidence were noted over the summer months (SWR 1.39 (CI 1.37–1.40)). This increase was less apparent for cSCCs, as higher incidence rates were observed in the months September-November (SWR 1.13 (CI 1.12–1.14)). The seasonal variation of CM was greater in women and younger people, in superficial spreading melanoma and lentigo maligna melanoma, for the extremities, in thinner lesions, and for stage I at diagnosis. The seasonal variation of cSCC was similar for both sexes, most marked in patients 45‐69 and ≥ 70, and for the extremities. ConclusionsOur findings showed a pronounced seasonal variation in the diagnosis of CM with a peak in the summer months. For cSCC, no evident peak was observed, but an increase in diagnosis was noted in fall. Both CM and cSCC showed strong seasonal effects for the extremities.

Functional gastrointestinal disorders frequency by Rome IV criteria

IntroductionFunctional gastrointestinal disorders (FGIDs) are a very common pediatric disease, with strong implications for children and their families. We aimed to determine their frequency in our environment (per Rome IV criteria) and to establish if there is seasonal variability in diagnosis. MethodsDescriptive, prospective study. For 12 months, children under 16 years of age with suspected FGIDs who had a first pediatric gastroenterology consultation were included and classified according to Rome IV criteria. Statistical analysis was done with SPSS v22. Results574 children received consultations, 67% were >4 years of age. FGIDs were suspected in 44.6% of the patients, 32.4% were diagnosed according to Rome IV criteria (16.4% <4 years, 40.3% >4 years). 51.1% were female, average age of 8.4 ± 4.2 years and mean of 7 months of symptoms until diagnosis (range 3–150). In patients <4 years, the most common disorders were functional constipation (48.4%), regurgitation (22.5%) and functional diarrhea (16.1%); in patients >4 years of age, functional abdominal pain (29%), functional dyspepsia (28.4%) and functional constipation (16.8%) were most frequent. We didn’t discern seasonal variations in diagnosis in the global study population (p = 0.96) or by age group (<4 p = 0.51; >4 p = 0.57). ConclusionsFGIDs account for one third of our patients’ consultations. While the Rome IV criteria are more inclusive than before, almost 30% of patients with suspected FGIDs don’t meet said criteria. Although a seasonal difference regarding diagnosis was observed, it wasn’t statistically significant either in the sample group as a whole or by age group.

Seasonal Variations in the Diagnosis of Testicular Germ Cell Tumors: A National Cancer Registry Study in Austria.

Simple SummarySeasonal variations in cancer diagnosis could already be demonstrated in prostate and breast cancer. The reasons for this observed seasonal pattern are still unclear. The health care system or other determinants such as the protective function of vitamin D3 in carcinogenesis could be assumed as one explanation. Testicular germ cell tumors are the most common developed malignancy among young men. The aim of our study was to investigate, for the first time, the seasonal variations in the clinical diagnosis of testicular germ cell tumors. We have been able to confirm that the frequency of monthly newly diagnosed cases of testicular cell tumors in Austria has a strong seasonality, with a significant reduction in the tumor incidence during the summer months and an increase during the winter months.We conducted a retrospective National Cancer Registry study in Austria to assess a possible seasonal variation in the clinical diagnosis of testicular germ cell tumors (TGCT). In total, 3615 testicular cancer diagnoses were identified during an 11-year period from 2008 to 2018. Rate ratios for the monthly number of TGCT diagnoses, as well as of seasons and half-years, were assessed using a quasi-Poisson model. We identified, for the first time, a statistically significant seasonal trend (p < 0.001) in the frequency of monthly newly diagnosed cases of TGCT. In detail, clear seasonal variations with a reduction in the tumor incidence during the summer months (Apr–Sep) and an increase during the winter months (Oct–Mar) were observed (p < 0.001). Focusing on seasonality, the incidence during the months of Oct–Dec (p = 0.008) and Jan–Mar (p < 0.001) was significantly higher compared to the months of Jul–Sep, respectively. Regarding histopathological features, there is a predominating incidence in the winter months compared to summer months, mainly concerning pure seminomas (p < 0.001), but not the non-seminoma or mixed TGCT groups. In conclusion, the incidence of TGCT diagnoses in Austria has a strong seasonal pattern, with the highest rate during the winter months. These findings may be explained by a delay of self-referral during the summer months. However, the hypothetical influence of vitamin D3 in testicular carcinogenesis underlying seasonal changes in TGCT diagnosis should be the focus of further research.

Seasonal variations in the diagnosis of the top 10 cancers in Korea: A nationwide population-based study using a common data model.

A better understanding of seasonal variations in cancer diagnosis may be the first step toward optimal resource distribution in the National Cancer Screening Program (NCSP). This study aimed to identify seasonal variations in the diagnosis of the top 10 major cancers in Korea. We conducted a retrospective, observational cohort study in participants aged≥20years between 2012 and 2016 from the Health Insurance Review and Assessment-National Patient Sample database, previously converted to a common data model. We assessed the overall seasonal variations in the 10 major cancers. We analyzed the following top 10 cancers: stomach (n=3435), colorectal (n=5368), liver (n=7605), pancreatic (n=2946), gallbladder (n=899), lung (n=1598), prostate (n=2897), thyroid (n=1966), breast (n=1313), and kidney (n=668) cancers. All cancers showed similar seasonal variations in diagnosis, with a significant winter peak. A winter peak in diagnosis was observed for NCSP-covered cancers, such as stomach, colon, liver, and breast cancers, as well as other cancers not covered by the NCSP. The winter peak for cancer diagnosis was the highest for breast cancer (74.4%) followed by thyroid (51.0%) and stomach cancers, whereas it was the lowest for pancreatic cancer followed by prostate and colorectal cancers. Significant seasonal variations were found in the diagnosis of the top 10 major cancers, with a winter peak, which may be explained by the participants' behavior pattern with respect to the NCSP. Our findings suggest that trading off of NCSP healthcare resources between winter and other seasons may be beneficial.

Frecuencia de trastornos gastrointestinales funcionales según criterios Roma IV

IntroductionFunctional gastrointestinal disorders (FGIDs) are a very common pediatric disease, with strong implications for children and their families. We aimed to determine their frequency in our environment (per Rome IV criteria) and to establish if there is seasonal variability in diagnosis. Material and methodsDescriptive, prospective study. For 12 months, children under 16 years of age with suspected FGIDs who had a first pediatric gastroenterology consultation were included and classified according to Rome IV criteria. Statistical analysis was done with SPSS v22. Results574 children received consultations, 67% were >4 years of age. FGIDs were suspected in 44.6% of the patients, 32.4% were diagnosed according to Rome IV criteria (16.4%, <4 years; 40.3%, >4 years). 51.1% were female, average age of 8.4±4.2 years and mean of 7 months of symptoms until diagnosis (range 3–150). In patients <4 years, the most common disorders were functional constipation (48.4%), regurgitation (22.5%) and functional diarrhea (16.1%); in patients >4 years of age, functional abdominal pain (29%), functional dyspepsia (28.4%) and functional constipation (16.8%) were most frequent. We did not discern seasonal variations in diagnosis in the global study population (p=.96) or by age group (< 4, P=.51; > 4, P=.57). ConclusionsFGIDs account for one third of our patients’ consultations. While the Rome IV criteria are more inclusive than before, almost 30% of patients with suspected FGIDs do not meet said criteria. Although a seasonal difference regarding diagnosis was observed, it was not statistically significant either in the sample group as a whole or by age group.

There is no Seasonal Variation but Regional Variation Exists Between Adults and Children in Hospitalization Rates of Eosinophilic Esophagitis (EoE) in the United States

Introduction: Prior studies have shown that incidence of EoE has been rising and EoE may have a seasonal and regional variation. We hypothesize that the hospitalization rates for EoE has been rising in both pediatric and adult population in the United States. We also hypothesize that the hospitalization rates between the two age groups vary with seasons and geographical location. Methods: Between 2009 to 2012, data was extracted from the National Inpatient Sample on all patients with Eosinophilic Esophagitis (ICD 9 CM: 530.13). Information prior to 2008 was excluded as EoE was given a specific ICD 9 Code only in 2008. In order to remove bias and confounding factors which may mimic symptoms of EoE, exclusion criteria was applied (ICD 9 CM:530.81, 530.85, 530.0, 530.5, 530.6, 530.10, 530.11, 530.12, 530.19, 150). Hospitalization rates of EoE were analyzed annually for all age groups during the study period. EoE Hospitalization rates were also assessed for four seasons (Summer, Spring, Fall and Winter), for each of the US States and Urban versus Rural Location in the US. Analyses were performed using SAS version 9.3. Results: During the study period, a total of 2004 patients with EoE were admitted to the hospitals in United States. Of these, 1180 cases were of adult EoE and 824 cases of pediatric EoE were identified.We noted that the EoE related hospitalization rates increased to 924 in 2012 from 567 in 2009 with higher rates for adults compared to children (P<0.0001) [Fig 1A].There was no significant seasonal variation in hospitalization rates of EoE between adults and children [Fig 1B]. Hospitalization rates varied among the US states with highest rates in some states with dry environment (Arizona, California, Florida, Texas) and lowest among the others with colder climate (North Dakota, Maine, South Dakota) [Fig 2].Similarly, the hospitalization rates were highest in the Central counties of metro areas of >=1 million population and lowest for Not metropolitan or micropolitan counties, significantly higher for adults compared to children (P=0.01) [Fig 3].Figure: Annual Hospitalization Trends of EoE Fig 1B: Seasonal Variation in Hospitalization of EoE.Figure: US State-Wise Hospitalization Trends of EoE.Figure: Urban vs Rural Hospitalization Trends of EoE.Conclusion: EoE related hospitalization has been rising in the United States. We note that EoE doesn't have a seasonal variation in diagnosis and hospitalization between adults and childen. We highlight that urbanization and residence in areas with dry and arid climate may have played a role in the pathogenesis and the rising trends of EoE with significant effect in adults. Further studies are needed to confirm these findings.

Seasonal distribution of initial diagnosis and clinical recrudescence of eosinophilic esophagitis: a systematic review and meta-analysis.

The association between seasonality and diagnosis and/or recrudescence of eosinophilic esophagitis (EoE) remains unclear, with some studies demonstrating a higher diagnostic rate in those months with a higher aeroallergen load while others rule out this association. We performed a systematic search of the MEDLINE, EMBASE, and SCOPUS databases for studies on the seasonality of the initial diagnosis or recrudescence (i.e., food bolus impaction) of EoE. Summary estimates, including 95% confidence intervals, were calculated for seasonal variation in diagnosis or incidence of food bolus impaction. A random-effects meta-regression model was made using aggregate-level data to compare seasonality in EoE diagnosis and recrudescence. Publication bias risks were assessed by means of funnel plot analysis. Of 1078 references found, data were finally collected from 18 studies which included a total of 16,846 EoE patients. Of all new cases of EoE diagnosed per year, 27.1% were diagnosed in spring and 21.5% in winter. No overall statistical differences in the annual seasonal distribution of newly diagnosed EoE cases were observed in the random-effects meta-regression model (P = 0.132). Similarly, a homogenous distribution of episodes of EoE recrudescence throughout the year was noted, with no significant differences between seasons (P = 0.699). No significant publication bias was found. This systematic review found no significant variations in the seasonal distribution of either the diagnosis or clinical recrudescence of EoE throughout the year.

Seasonal variation in diagnosis of invasive cutaneous melanoma in Eastern England and Scotland

BackgroundWorldwide, the incidence of cutaneous melanoma has been reported to be highest in the summer and lowest in the winter. Northern Irish data suggested seasonal variation for women only, especially those with thinner melanomas, sited on limbs. We interrogated two larger UK cancer registries for temporal differences in melanoma diagnosis and associated patient characteristics. MethodsMelanomas diagnosed from 2006 to 2010 in the Eastern England and Scottish cancer registries (n=11,611) were analysed by month of diagnosis, patient demographics and melanoma characteristics, using descriptive and multivariate modelling methods. ResultsMore patients with melanoma were diagnosed in the summer months (June 9.9%, July 9.7%, August 9.8%) than the winter months (December 7.2%, January 7.2%, February 7.1%) and this pattern was consistent in both regions. There was evidence that the seasonal patterns varied by sex (p=0.015), melanoma thickness (p=0.002), body site (p=0.006), and type (superficial spreading melanomas p=0.005). The seasonal variation was greatest for diagnosis of melanomas occurring on the limbs. ConclusionThis study has confirmed seasonal variation in melanoma diagnosis in Eastern England and Scotland across almost all population demographics and melanoma characteristics studied, with higher numbers diagnosed in the summer months, particularly on the limbs. Seasonal patterns in skin awareness and related help-seeking are likely to be implicated. Targeted patient interventions to increase sun awareness and encourage year-long skin inspection are warranted.

Seasonal variation in detection of oesophageal eosinophilia and eosinophilic oesophagitis.

Seasonal variation has been reported in diagnosis of eosinophilic oesophagitis (EoE), but results are not consistent across studies and there are no national-level data in the USA. To determine if there is seasonal variation in diagnosis of oesophageal eosinophilia and EoE in the USA, while accounting for factors such as climate zone and geographic variation. This was a cross-sectional study using a USA national pathology database. Patients with oesophageal eosinophilia (≥15 eosinophils per high-power field) comprised the primary case definition and were compared to those with normal oesophageal biopsies. We calculated the crude and adjusted odds of oesophageal eosinophilia by season, as well as by day of the year. Sensitivity analyses were performed using more restrictive case definitions of EoE, and after stratification by climate zone. Exactly, 14524 cases with oesophageal eosinophilia and 90459 normal controls were analysed. The adjusted odds of oesophageal eosinophilia were higher in the late spring and summer months, with the highest odds in July (aOR: 1.13; 95% CI: 1.03-1.24). These findings persisted with increasing levels of oesophageal eosinophilia, as well as across EoE case definitions. Seasonal variation was strongest in temperate and cold climates, and peak diagnosis varied by climate zone. There is a mild but consistent seasonal variation in the diagnosis of oesophageal eosinophilia and EoE, with cases more frequently diagnosed during summer months. These findings take into account climate and geographic differences, suggesting that aeroallergens may contribute to disease development or flare.

Demographics of 3929 ankle injuries, seasonal variation in diagnosis and more fractures are diagnosed in winter

IntroductionAn audit took place to look at the diagnostic or pick-up rate of ankle fractures. A seasonal variation was discovered. Although it is expected that more fractures may be seen in wet or icy periods, an excess of X-rays taken in the summer months has not been previously registered. MethodAn automated X-ray system was looked at to see the number of X-rays taken and the diagnostic yield. ResultsWe reviewed ankle X-rays of 3929 patients over a 24-month period between 1 July 2009 and 31 June 2011; of which, 612 patients were found to have fractured their ankle giving a pick-up rate of 0.16. This is less than what might be expected with strict application of Ottawa rules. The pick-up rate fluctuated each month from an admirable 0.35 fractures per X-ray ordered in December 2009 to a lowly 0.06 fractures per X-ray in May 2010. The same pattern was noted for the other year. For both Decembers, the fewest number of X-rays were taken at 80 and 140, the most at 200 and 240 in May for both years. Less X-rays were taken in for all winter months. For younger age groups, males dominated with the crossover to females dominating in the fifth decade. ConclusionWe postulate that summertime sports and recreational injuries may cause less fractures than at winter periods but result in more X-rays taken. We have reviewed our practice to try to improve our diagnostic rates; the basic tenets of Ottawa rules including the presence of bony tenderness and weight-bearing status have been reinforced in our teaching sessions. It is highly likely that strict application of these methods will decrease the number of X-rays taken and improve our pick-up rates.

Rapidly increasing incidence of eosinophilic esophagitis in a large cohort

Recent literature has shown increasing incidence and prevalence rates of eosinophilic esophagitis (EoE). However, data are mainly based on small studies and come from centers dedicated to EoE. Aim of this study was to estimate the incidence rates of EoE by using a large database. We performed a cross-sectional study of the pathology reports describing esophageal eosinophilia from 1996 through 2010, using the nationwide network and registry of histo- and cytopathology in The Netherlands (PALGA). All histopathology reports nationwide enter this database. We classified cases according to the diagnosis made by the pathologist. Annual incidence rates of EoE were estimated. Our search criteria yielded 8838 positive pathology reports. Eosinophilic esophagitis was diagnosed in 674 patients, of which 74% were men. In another 174 patients, no distinction was made between eosinophilia caused by gastro-esophageal reflux disease or EoE. The incidence of EoE increased considerably over the years, being 0.01 in 1996, 0.01 in 2000, 0.14 in 2005, and 1.31 per 100,000 persons in 2010. Eosinophilic esophagitis was diagnosed in all age groups, but in 2010 the highest incidence was seen in 20-29 years old males, in whom it was estimated to be 3.23 per 100,000 persons. The incidence in children was 0.73 per 100,000 in 2010. No seasonal variation in diagnosis of EoE was observed. In this large study, we found robust data on increasing incidence rates of pediatric and adult EoE in the past 15 years. This rapidly increasing incidence has not reached a plateau yet.

Su1139 Eosinophilic Esophagitis is More Commonly Found in Asthma Patients With an Allergic Phenotype but is Less Likely in Those on Steroid Inhalers

Background Recent literature has suggested that the incidence and prevalence of eosinophilic esophagitis (EoE) are increasing. Aim of this study was to estimate the true populationbased incidence rates of EoE by using a large national database. Methods We performed a cross-sectional study of the pathology reports describing esophageal eosinophilia from 1996 through 2010, using the Dutch nationwide registry of histopathology reports (PALGA). All histopathology reports of the Netherlands (16,615,394 inhabitants in 2010) enter this database. Cases were identified and classified according to the diagnosis made by the pathologist. Annual incidence rates of EoE were estimated and adjusted for age and sex. Results Our search yielded 8,838 pathology reports. Diagnosis of EoE was made in 674 patients, of which 501 (74.3%) were male and 173 (25.7%) female. In another 174 cases no difference was made between eosinophilia caused by reflux disease or by EoE. The incidence of EoE increased considerably with time, being 0.01 (95% CI 0-0.02) in 1996, 0.01 (95% CI 0-0.03) in 2000, 0.14 (95% CI 0.08-0.20) in 2005, and 1.31 (95% CI 1.131.48) per 100,000 persons per year in 2010. EoE was diagnosed in all age groups, but the highest incidence was seen in patients in the male 20-29 year age group in 2010, in which it was estimated to be 3.23 (95% CI 2.13-4.33) per 100,000 persons. The incidence in children was 0.73 (95% CI 0.45-1.02) per 100,000 persons in 2010. No seasonal variation in diagnosis of EoE was seen. Conclusion We found a rapidly increasing incidence of EoE in the past 15 years that did not reach a plateau yet. This augmentation could be explained on the one hand by an increased awareness of EoE by physicians and pathologists, and on the other hand by a true increase of incidence of the disease. The latter would be in line with the parallel increase in other atopic diseases.

Seasonal variation in diagnosis of eosinophilic esophagitis

Seasonal variation in diagnosis of eosinophilic esophagitis

Seasonal Variation in the Diagnosis of Eosinophilic Esophagitis

Purpose: The etiology of eosinophilic esophagitis (EoE) is unknown, though allergens may play a pathogenic role. The purpose of this study was to examine seasonal variation in diagnosis of EoE as compared to gastroesophageal reflux disease (GERD). We hypothesized that EoE would be more frequently diagnosed at times of high allergen burden (spring/summer) and there would be no seasonal variation in GERD diagnosis. Methods: We performed a retrospective study of the University of North Carolina EoE clinicopathologic database which contains information on patients with esophageal eosinophilia from 2000–2007. Cases of EoE were defined as having ≥15 eosinophils per high-powered field (0.23 mm2; eos/hpf) with at least one typical symptom (eg dysphagia, heartburn, or feeding intolerance) and with other causes of esophageal eosinophilia excluded. Incident cases were categorized by their esophageal biopsy date. Controls were patients with GERD who also underwent endoscopy and biopsy over this time course. Cases of EoE and GERD were stratified by season and month of diagnosis and compared with chi-square. Results: 149 cases of EoE were identified (mean age 24.5 yrs; range: 8 mos-77 yrs); 72 were 18 years or older (48%), 105 (70%) were male, and 119 (80%) Caucasian. 684 GERD controls were identified (mean age 44.1 yrs; range: 4 mos–87 yrs); 49% were male and 81% Caucasian. 19% of EoE cases were diagnosed in the winter (Dec–Feb), 19% in the spring (Mar–May), 34% in the summer (June-Aug), and 28% in the fall (Sept-Nov; see Figure) compared with 23%, 29%, 23%, and 25% of the GERD cases, respectively (P= 0.01). The highest proportion of EoE cases was diagnosed in August (14%) compared with 7% of GERD cases (P= 0.04). Tissue eosinophil counts were also highest during the summer (77 eos/hpf) compared with winter (57 eos/hpf), with a peak level in August (95 eos/hpf). There was no difference in EoE diagnosis based on age, atopic disease, food allergy, or asthma.FigureConclusion: There is evidence of seasonal variation in the diagnosis of EoE at our center, but not in the diagnosis of GERD. The highest percentage of cases of EoE are diagnosed over the summer, which was also the time of highest tissue eosinophil counts. These findings may help generate hypotheses about environmental etiologies of EoE.

Seasonal variation in the diagnosis of type 1 diabetes in south-east Sweden

With the aim to survey the seasonal pattern of diagnosis of type 1 diabetes we included all 1903 children <16 years of age and who had been diagnosed with type 1 diabetes between 1977 and 2001 in the south-east of Sweden. To investigate the seasonal pattern a mixture of two cosine functions was included in a logistic regression model. There was a clear seasonal variation over the years ( p < 0.001). Children in the oldest age group (11–15 years) showed the most obvious seasonal variation ( p < 0.001). Children with a short duration of symptoms had about the same seasonal variation as children with a long duration. Both children with and without an infection 3 months prior to diagnosis showed significant seasonal variation ( p < 0.001) although the seasonal pattern differed between the two groups ( p < 0.001). As the incidence of diabetes increased during the 25 years the study period was divided into periods of 5 years and it was only during the two last periods that significant seasonal variation occurred. There is a clear seasonal variation in diagnosis of type 1 diagnosis in children and the results suggest that children with a less aggressive disease process at diagnosis were most responsible for this variation. Children with and without prior infection showed a different seasonal pattern.

Incidence and differences in urban-rural seasonal variation of type 1 (insulin-dependent) diabetes in Wisconsin.

In a hospital-based records study of Type 1 (insulin-dependent) diabetes mellitus among persons aged 0 to 29 years in two Wisconsin, USA counties (1970-79), the age-adjusted yearly incidence rate for white males (16.4/100,000) was significantly higher than for white females (11.6/100,000) (p = 0.006). Overall age-adjusted rates are similar to rates previously reported for the United States and the northern European countries of Denmark and Norway. Seasonal variation in diagnosis was found for total cases and males aged 10 to 19 years. A striking difference also was found in seasonal diagnosis between urban and rural cases. A diagnosis peak in the third and fourth quarter among rural cases contrasted with even quarterly distribution among urban cases. In addition, 52% of rural male cases aged 10 to 19 years were diagnosed during the fourth quarter while no seasonal pattern occurred among urban males the same ages. These findings identify subgroups for focus of future etiologic investigations.

The clinical features of diabetes with coexisting autoimmune thyroid disease.

A study was made of the clinical features of diabetics with coexisting Graves' disease (n = 117) or primary hypothyroidism (n = 98). Those with Graves' disease developed thyroid dysfunction and diabetes at an earlier age than patients with primary hypothyroidism. There was, however, no difference between the two groups in respect of sex ratio nor proportion of subjects requiring insulin treatment. In contrast to the general diabetic population, 87% of diabetics with thyroid disease were female, 56% required insulin treatment and of patients requiring insulin from diagnosis, the median age at diagnosis of diabetes was 36 years. A strong correlation was observed between age at diagnosis of diabetes and that of hyperthyroidism (r = 0.71, p less than 0.001) or hypothyroidism (r = 0.65, p less than 0.001). With increasing age at diagnosis of diabetes the interval between diagnosis of diabetes and thyroid disease diminished. The mean +/- SEM interval between diagnosis of diabetes and that of thyroid dysfunction was longer in hypothyroid (6.7 +/- 1.2 years) than in hyperthyroid diabetics (-2.4 +/- 1.2 years). Neither insulin-dependent nor non-insulin dependent diabetics with associated thyroid disease exhibited a significant seasonal variation in diagnosis or symptomatic onset of diabetes. It is conceivable that where diabetes accompanies autoimmune thyroid disease in the same patient, both conditions may share a common and coincident pathogenesis which is unrelated to acute environmental influences.

Seasonal onset of insulin dependent diabetes in relation to sex and age at onset.

All newly diagnosed insulin dependent diabetics presenting consecutively to the Diabetic Department of the Royal Infirmary from the City of Edinburgh or its environs, between the years 1964 and 1977, were analysed for sex (297 males, 205 females), age at diagnosis (range 10--75 years), month of diagnosis, duration of symptoms and month of symptomatic onset. Males aged 10--19 years showed a significant seasonal variation in diagnosis (p less than 0.025) with an increase in autumn and winter months which was not seen in females aged 10--19 years nor in patients of either sex aged more than 19 years at diagnosis. The duration of diabetic symptoms increased with increasing age at diagnosis in both males and females and was consistently greater in females than in males for each age group at diagnosis. When the month of symptomatic onset was considered in relation to sex and age at diagnosis, having excluded patients with duration of symptoms of more than three months, only males aged 10--19 years at diagnosis showed a significant seasonal variation in incidence (p less than 0.005).