T ype 1 diabetes is associated with other autoimmune diseases. Many diabetes centers routinely sc... more T ype 1 diabetes is associated with other autoimmune diseases. Many diabetes centers routinely screen patients with type 1 diabetes for autoimmune thyroid disease (ATD). The presence of two autoimmune diseases raises the possibility of polyendocrine autoimmune disease. The association of autoimmune adrenal insufficiency, or Addison's disease, with type 1 diabetes is described in case reports dating back more than a century (1,2). Studies have i l l u s t r a t e d s h a r e d H L A a l l e l e s (DQA1*0501, for example) among patients with type 1 diabetes, ATD, and Addison's disease (3,4). Pancreatic islet cell antibodies have been detected in 6.2% of patients with Addison's disease ( ). Yet, it is unclear whether patients with type 1 diabetes should be routinely screened for Addison's disease. Our study's objective was to determine whether routine screening for Addison's disease is warranted in children with both type 1 diabetes and ATD. Children were diagnosed with thyroid disease if they had thyroid peroxidase antibodies (TPOs Ͼ50 Ku/l) and/or were receiving thyroid hormone replacement for primary hypothyroidism. A population of children with type 1 diabetes but without thyroid disease was also screened. The study population consisted of 114 children with type 1 diabetes, 35 (25 girls and 10 boys) with thyroid disease (28 on L- thyroxine) and 79 (42 girls and 37 boys) without thyroid disease (normal thyroidstimulating hormone and TPO Ͻ50 Ku/ l). Adrenal antibodies were measured by standard immunofluorescent technique (Nova Century Scientific-Immco antiadrenal slides), and TPOs were measured by an automated electrochemiluminescence immunoassay (Roche Elecsys 2010).
Aims Several studies confirmed the growing rate of Type 1 diabetes mellitus in childhood coincidi... more Aims Several studies confirmed the growing rate of Type 1 diabetes mellitus in childhood coinciding with increasing diagnosis of viral infections. A study investigating the incidence of Type 1 diabetes during 1996-1997 showed a higher notification of viral infections in the Pavia District. The aim was to confirm these results. Methods This study evaluated the relationship between new cases of Type 1 diabetes and those of measles, mumps and rubella in 1996-2001, analysing data of newly-diagnosed Type 1 diabetes children, aged 0-14 years and enrolled into the RIDI (Italian Insulin-dependent Diabetes Registry) during the same years. Measles, rubella and mumps rates were calculated using as denominator the estimated 'population at risk', represented by the number of 0-to 14 year-old subjects who did not undergo the MMR (measles, mumps and rubella) vaccination. In order to investigate the association between Type 1 diabetes incidence and measles, rubella and mumps respectively, Spearman's rank correlation was used. The analysis of the whole Registries data did not at first show any statistical significance between age-standardized Type 1 diabetes incidence density and estimated rates of measles, mumps and rubella notifications. Excluding data from Sardinia Registry, a significant association was observed between Type 1 diabetes incidence and mumps (P = 0.034) and rubella (P = 0.014), respectively, while there was no statistical significance between the incidence of measles cases and diabetes rates (P = 0.269). Conclusions According to our findings, mumps and rubella viral infections are associated with the onset of Type 1 diabetes. The statistical significance observed after exclusion of the Sardinian data suggests that other environmental factors may operate over populations with different genetic susceptibility.
La diffusione della terapia insulinica sottocutanea continua con microinfusore (CSII) \ue8 in con... more La diffusione della terapia insulinica sottocutanea continua con microinfusore (CSII) \ue8 in continuo aumento nel mondo, grazie anche al miglioramento della tecnologia degli strumenti. Scopo di questo lavoro \ue8 stato quello di valutare lo stato attuale della CSII in Italia. A tal fine ai responsabili di 272 strutture diabetologiche che seguono pazienti in terapia con microinfusore \ue8 stato inviato un questionario che indagava aspetti clinici, tecnici e organizzativi della terapia con microinfusore. Duecentodiciassette strutture (79,8%) hanno partecipato all\u2019indagine. Dai dati raccolti \ue8 emerso che a fine aprile 2013 in tali strutture vi erano 10.152 pazienti in terapia con microinfusore, quasi tutti (98,2%) affetti da diabete di tipo 1, prevalentemente adulti (82,4%) e di sesso femminile (57%). La diffusione della CSII risultava molto disomogenea tra le diverse Regioni e anche tra le diverse strutture diabetologiche di una stessa Regione: solo il 59% delle strutture seguiva pi\uf9 di 20 pazienti ciascuna. Motivo principale per iniziare la CSII era la ricerca del buon controllo glicemico. Il drop-out (8,65% dei casi), avveniva soprattutto per problemi legati alla portabilit\ue0 della pompa o al mancato raggiungimento del target glicemico. La maggior parte dei pazienti (61%) utilizzava un microinfusore tradizionale, il 39% un microinfusore integrato (32%) o associato (7%) a un dispositivo per il monitoraggio in continuo della glicemia. Le funzioni avanzate del microinfusore venivano mediamente utilizzate solo dal 68% dei pazienti e il sensore era utilizzato mediamente solo per 12 giorni al mese. L\u201981% delle strutture garantiva una reperibilit\ue0 24 ore su 24. Solo nel 40% delle strutture per adulti e nel 50% di quelle pediatriche i pazienti venivano seguiti da un team completo. In conclusione, la CSII si sta sempre pi\uf9 diffondendo in Italia, sia tra i pazienti adulti sia tra quelli pediatrici. \uc8 auspicabile una maggiore uniformit\ue0 tra le diverse Regioni e un uso pi\uf9 adeguato della tecnologia stessa
Journal of the American Heart Association, Jan 5, 2017
The independent prognostic impact of diabetes mellitus (DM) and prediabetes mellitus (pre-DM) on ... more The independent prognostic impact of diabetes mellitus (DM) and prediabetes mellitus (pre-DM) on survival outcomes in patients with chronic heart failure has been investigated in observational registries and randomized, clinical trials, but the results have been often inconclusive or conflicting. We examined the independent prognostic impact of DM and pre-DM on survival outcomes in the GISSI-HF (Gruppo Italiano per lo Studio della Sopravvivenza nella Insufficienza Cardiaca-Heart Failure) trial. We assessed the risk of all-cause death and the composite of all-cause death or cardiovascular hospitalization over a median follow-up period of 3.9 years among the 6935 chronic heart failure participants of the GISSI-HF trial, who were stratified by presence of DM (n=2852), pre-DM (n=2013), and non-DM (n=2070) at baseline. Compared with non-DM patients, those with DM had remarkably higher incidence rates of all-cause death (34.5% versus 24.6%) and the composite end point (63.6% versus 54.7%)...
Continuous subcutaneous insulin infusion (CSII) is increasingly being used worldwide, mostly than... more Continuous subcutaneous insulin infusion (CSII) is increasingly being used worldwide, mostly thanks to technical improvements. This study examined the current status of CSII in Italy. Physicians in charge of 272 diabetes centers caring for patients using CSII were sent a questionnaire investigating clinical features, pump technology and management of these patients; a large proportion (217 centers, 79.8%) joined the study. By end-April 2013, data had been collected on 10152 patients treated with CSII; 98.2% had type 1 diabetes, 82.4% were adults, 57% female. Only just over half the centers (59%) managed more than 20 CSII patients each. The distribution of patients varied widely both among and within different regions. The main indication for CSII was the de- sire to improve glycemic control. Dropouts (8.65%) were mainly due to difficulties with pump wearability or non-optimal glycemic control. Among CSII patients 61% used a traditional pump, 39% a sensor augmented pump. Only 68% use...
Stable genetic background makes individuals from the Mediterranean island of Sardinia ideal to de... more Stable genetic background makes individuals from the Mediterranean island of Sardinia ideal to define the predictive power of islet-related autoantibodies (IRAs): glutamic acid decarboxylase antibodies (GADA), tyrosine phosphatase-like antibodies (IA-2A), islet cell antibodies (ICA) to identify T1DM progressors. The aims of the present study were: (1) determination of IRAs reference limits in healthy non-diabetic Sardinian schoolchildren (SSc). (2) Predictive power evaluation of IRAs as single or combined determination to identify islet to identify T1DM progressors. Between 1986 and 1994, 8448 SSc were tested for IRAs. All were followed up for 10 years. The predictive power of single or combination of IRAs was determined as hazard ratio (HR), sensitivity, specificity, area under the ROC curve, negative and positive predictive value (NPV, PPV). All 43 progressors to T1DM, but three showed at least one autoantibody positivity. HR for any single-autoantibody positivity was 55.3 times g...
Type 1 diabetes is an autoimmune disease. Genetics as well as environmental factors seem to play ... more Type 1 diabetes is an autoimmune disease. Genetics as well as environmental factors seem to play a role in the pathogenesis of type 1 diabetes. We sought to investigate the possible relationship between migration from Sardinia to a low incidence area of type 1 diabetes (Lombardy) and the prevalence of autoantibody positivity. We enrolled 554 Sardinian immigrants and 226 of their offspring. All subjects underwent a complete anamnestic evaluation. Fasting blood glucose, HbA1c, GADA and IA-2 were measured in all study participants. Additionally, the presence of risk haplotypes (HLA-DR3 -DR4 and DQB1/0302) was determined. After a seven-year follow-up, high genetic risk and/or autoantibody positivity subjects were re-evaluated. Among Sardinian immigrants, the prevalence of type 1 diabetes was 0.9%, while in the offspring group, the prevalence was 0.4%. After removing type 1 diabetic patients, the GADA prevalence was 2.4% in the immigrant group and 3.8% among their offspring. Among Sardin...
In the Sardinian population a very high incidence of insulindependent diabetes mellitus (IDDM) an... more In the Sardinian population a very high incidence of insulindependent diabetes mellitus (IDDM) and the lack of HLA-DR2 protective effect due to the high-frequency of the A2, Cw7, B17, 3F31, DR2, DQwl extended haplotype has been reported. This haplotype, carrying a Serine at position 57 of the DQB1*0502 allele, has been previously reported to be underrepresented in patients when compared to controls. In order to provide an explanation for this finding, we defined by RFLP analysis the HLA haplotype of 45 Sardinian IDDM patients and 49 controls. All DR-2DQw1 subjects were molecularly characterized at the HLA DQA and DQB loci. All DR2-positive patients and the vast majority of the DR2-positive controls had the DQB 1*0502 allele at the DR2-linked DQBl locus, with no statistically significant difference between the two groups. All DQAl genes were the ones expected, with only two exceptions. Nine out of 10 of the DRZpositive patients were compound heterozygotes for DQB 1 *020 1 /DQBl*O502 alleles; only this allele combination was significantly increased (p< 0.0003). Our data suggests that a) the DQB1*0502 allele is neutral for IDDM development and b) the susceptibility to IDDM in our DR2-positive patients is related to the compound hetrozygous state between the neutral DQAl*0102/DQB1*0502 and the I susceptibility DQA1*0501 /DQB1*0201 alleles.
The analysis of variation of risk for a given disease in space and time is a key issue in descrip... more The analysis of variation of risk for a given disease in space and time is a key issue in descriptive epidemiology. When the data are scarce, maximum likelihood estimates of the area‐specific risk and of its linear time‐trend can be seriously affected by random variation. In this paper, we propose a Bayesian model in which both area‐specific intercept and trend are modelled as random effects and correlation between them is allowed for. This model is an extension of that originally proposed for disease mapping. It is illustrated by the analysis of the cumulative prevalence of insulin dependent diabetes mellitus as observed at the military examination of 18‐year‐old conscripts born in Sardinia during the period 1936–1971. Data concerning the genetic differentiation of the Sardinian population are used to interpret the results.
approach to study the temporal trend and the geographical variation in the risk of type 1 diabete... more approach to study the temporal trend and the geographical variation in the risk of type 1 diabetes. The Sardinian Conscript Type 1 Diabetes Registry.
In 102 insulin-dependent diabetic patients without retinopathy and with visual acuity 20/20, the ... more In 102 insulin-dependent diabetic patients without retinopathy and with visual acuity 20/20, the Farnsworth-Munsell 100-Hue test was performed, and glycosylated hemoglobin (GlHb) levels were determined. In 70% of the patients, a dyschromatopsia in the yellow-blue axis (tritanopia) was found. No correlation existed between duration of diabetes and tritanopia. On the other hand, the degree of this visual defect was positively correlated with GlHb levels. Thus, dyschromatopsia might be associated with poor metabolic control. It is suggested that dyschromatopsia is a consequence of hypoxia at the neuroepithelial level. The high levels of GlHb could be a contributory cause of hypoxia by reduction of both oxygen release capacity and erythrocyte deformability.
BackgroundA high frequency of blue eyes and fair skin are reported in northern European Caucasian... more BackgroundA high frequency of blue eyes and fair skin are reported in northern European Caucasians with type 1 diabetes (T1D). Also there is an inverse relationship between latitude and T1D incidence. We determined whether iris colour and skin pigmentation are risk factors in a Caucasian population living in two Mediterranean regions located at the same latitude with higher ultraviolet B irradiance, but with different T1D incidence.MethodsWe studied iris colour in 281 consecutive subjects with T1D and 298 controls. Skin type was evaluated by melanin quantification.ResultsIn Lazio, blue eyes and fair skin type are significantly more common in T1D subjects than in controls (21 versus 9%, p = 0.002; 50 versus 35%, p < 0.001, respectively). In Sardinia, the frequency of blue eyes in T1D subjects is twice that in controls (5.8 versus 2.6% and significantly higher when compared to the expected calculated frequency in the entire population). By logistic regression analysis, only blue ey...
T ype 1 diabetes is associated with other autoimmune diseases. Many diabetes centers routinely sc... more T ype 1 diabetes is associated with other autoimmune diseases. Many diabetes centers routinely screen patients with type 1 diabetes for autoimmune thyroid disease (ATD). The presence of two autoimmune diseases raises the possibility of polyendocrine autoimmune disease. The association of autoimmune adrenal insufficiency, or Addison's disease, with type 1 diabetes is described in case reports dating back more than a century (1,2). Studies have i l l u s t r a t e d s h a r e d H L A a l l e l e s (DQA1*0501, for example) among patients with type 1 diabetes, ATD, and Addison's disease (3,4). Pancreatic islet cell antibodies have been detected in 6.2% of patients with Addison's disease ( ). Yet, it is unclear whether patients with type 1 diabetes should be routinely screened for Addison's disease. Our study's objective was to determine whether routine screening for Addison's disease is warranted in children with both type 1 diabetes and ATD. Children were diagnosed with thyroid disease if they had thyroid peroxidase antibodies (TPOs Ͼ50 Ku/l) and/or were receiving thyroid hormone replacement for primary hypothyroidism. A population of children with type 1 diabetes but without thyroid disease was also screened. The study population consisted of 114 children with type 1 diabetes, 35 (25 girls and 10 boys) with thyroid disease (28 on L- thyroxine) and 79 (42 girls and 37 boys) without thyroid disease (normal thyroidstimulating hormone and TPO Ͻ50 Ku/ l). Adrenal antibodies were measured by standard immunofluorescent technique (Nova Century Scientific-Immco antiadrenal slides), and TPOs were measured by an automated electrochemiluminescence immunoassay (Roche Elecsys 2010).
Aims Several studies confirmed the growing rate of Type 1 diabetes mellitus in childhood coincidi... more Aims Several studies confirmed the growing rate of Type 1 diabetes mellitus in childhood coinciding with increasing diagnosis of viral infections. A study investigating the incidence of Type 1 diabetes during 1996-1997 showed a higher notification of viral infections in the Pavia District. The aim was to confirm these results. Methods This study evaluated the relationship between new cases of Type 1 diabetes and those of measles, mumps and rubella in 1996-2001, analysing data of newly-diagnosed Type 1 diabetes children, aged 0-14 years and enrolled into the RIDI (Italian Insulin-dependent Diabetes Registry) during the same years. Measles, rubella and mumps rates were calculated using as denominator the estimated 'population at risk', represented by the number of 0-to 14 year-old subjects who did not undergo the MMR (measles, mumps and rubella) vaccination. In order to investigate the association between Type 1 diabetes incidence and measles, rubella and mumps respectively, Spearman's rank correlation was used. The analysis of the whole Registries data did not at first show any statistical significance between age-standardized Type 1 diabetes incidence density and estimated rates of measles, mumps and rubella notifications. Excluding data from Sardinia Registry, a significant association was observed between Type 1 diabetes incidence and mumps (P = 0.034) and rubella (P = 0.014), respectively, while there was no statistical significance between the incidence of measles cases and diabetes rates (P = 0.269). Conclusions According to our findings, mumps and rubella viral infections are associated with the onset of Type 1 diabetes. The statistical significance observed after exclusion of the Sardinian data suggests that other environmental factors may operate over populations with different genetic susceptibility.
La diffusione della terapia insulinica sottocutanea continua con microinfusore (CSII) \ue8 in con... more La diffusione della terapia insulinica sottocutanea continua con microinfusore (CSII) \ue8 in continuo aumento nel mondo, grazie anche al miglioramento della tecnologia degli strumenti. Scopo di questo lavoro \ue8 stato quello di valutare lo stato attuale della CSII in Italia. A tal fine ai responsabili di 272 strutture diabetologiche che seguono pazienti in terapia con microinfusore \ue8 stato inviato un questionario che indagava aspetti clinici, tecnici e organizzativi della terapia con microinfusore. Duecentodiciassette strutture (79,8%) hanno partecipato all\u2019indagine. Dai dati raccolti \ue8 emerso che a fine aprile 2013 in tali strutture vi erano 10.152 pazienti in terapia con microinfusore, quasi tutti (98,2%) affetti da diabete di tipo 1, prevalentemente adulti (82,4%) e di sesso femminile (57%). La diffusione della CSII risultava molto disomogenea tra le diverse Regioni e anche tra le diverse strutture diabetologiche di una stessa Regione: solo il 59% delle strutture seguiva pi\uf9 di 20 pazienti ciascuna. Motivo principale per iniziare la CSII era la ricerca del buon controllo glicemico. Il drop-out (8,65% dei casi), avveniva soprattutto per problemi legati alla portabilit\ue0 della pompa o al mancato raggiungimento del target glicemico. La maggior parte dei pazienti (61%) utilizzava un microinfusore tradizionale, il 39% un microinfusore integrato (32%) o associato (7%) a un dispositivo per il monitoraggio in continuo della glicemia. Le funzioni avanzate del microinfusore venivano mediamente utilizzate solo dal 68% dei pazienti e il sensore era utilizzato mediamente solo per 12 giorni al mese. L\u201981% delle strutture garantiva una reperibilit\ue0 24 ore su 24. Solo nel 40% delle strutture per adulti e nel 50% di quelle pediatriche i pazienti venivano seguiti da un team completo. In conclusione, la CSII si sta sempre pi\uf9 diffondendo in Italia, sia tra i pazienti adulti sia tra quelli pediatrici. \uc8 auspicabile una maggiore uniformit\ue0 tra le diverse Regioni e un uso pi\uf9 adeguato della tecnologia stessa
Journal of the American Heart Association, Jan 5, 2017
The independent prognostic impact of diabetes mellitus (DM) and prediabetes mellitus (pre-DM) on ... more The independent prognostic impact of diabetes mellitus (DM) and prediabetes mellitus (pre-DM) on survival outcomes in patients with chronic heart failure has been investigated in observational registries and randomized, clinical trials, but the results have been often inconclusive or conflicting. We examined the independent prognostic impact of DM and pre-DM on survival outcomes in the GISSI-HF (Gruppo Italiano per lo Studio della Sopravvivenza nella Insufficienza Cardiaca-Heart Failure) trial. We assessed the risk of all-cause death and the composite of all-cause death or cardiovascular hospitalization over a median follow-up period of 3.9 years among the 6935 chronic heart failure participants of the GISSI-HF trial, who were stratified by presence of DM (n=2852), pre-DM (n=2013), and non-DM (n=2070) at baseline. Compared with non-DM patients, those with DM had remarkably higher incidence rates of all-cause death (34.5% versus 24.6%) and the composite end point (63.6% versus 54.7%)...
Continuous subcutaneous insulin infusion (CSII) is increasingly being used worldwide, mostly than... more Continuous subcutaneous insulin infusion (CSII) is increasingly being used worldwide, mostly thanks to technical improvements. This study examined the current status of CSII in Italy. Physicians in charge of 272 diabetes centers caring for patients using CSII were sent a questionnaire investigating clinical features, pump technology and management of these patients; a large proportion (217 centers, 79.8%) joined the study. By end-April 2013, data had been collected on 10152 patients treated with CSII; 98.2% had type 1 diabetes, 82.4% were adults, 57% female. Only just over half the centers (59%) managed more than 20 CSII patients each. The distribution of patients varied widely both among and within different regions. The main indication for CSII was the de- sire to improve glycemic control. Dropouts (8.65%) were mainly due to difficulties with pump wearability or non-optimal glycemic control. Among CSII patients 61% used a traditional pump, 39% a sensor augmented pump. Only 68% use...
Stable genetic background makes individuals from the Mediterranean island of Sardinia ideal to de... more Stable genetic background makes individuals from the Mediterranean island of Sardinia ideal to define the predictive power of islet-related autoantibodies (IRAs): glutamic acid decarboxylase antibodies (GADA), tyrosine phosphatase-like antibodies (IA-2A), islet cell antibodies (ICA) to identify T1DM progressors. The aims of the present study were: (1) determination of IRAs reference limits in healthy non-diabetic Sardinian schoolchildren (SSc). (2) Predictive power evaluation of IRAs as single or combined determination to identify islet to identify T1DM progressors. Between 1986 and 1994, 8448 SSc were tested for IRAs. All were followed up for 10 years. The predictive power of single or combination of IRAs was determined as hazard ratio (HR), sensitivity, specificity, area under the ROC curve, negative and positive predictive value (NPV, PPV). All 43 progressors to T1DM, but three showed at least one autoantibody positivity. HR for any single-autoantibody positivity was 55.3 times g...
Type 1 diabetes is an autoimmune disease. Genetics as well as environmental factors seem to play ... more Type 1 diabetes is an autoimmune disease. Genetics as well as environmental factors seem to play a role in the pathogenesis of type 1 diabetes. We sought to investigate the possible relationship between migration from Sardinia to a low incidence area of type 1 diabetes (Lombardy) and the prevalence of autoantibody positivity. We enrolled 554 Sardinian immigrants and 226 of their offspring. All subjects underwent a complete anamnestic evaluation. Fasting blood glucose, HbA1c, GADA and IA-2 were measured in all study participants. Additionally, the presence of risk haplotypes (HLA-DR3 -DR4 and DQB1/0302) was determined. After a seven-year follow-up, high genetic risk and/or autoantibody positivity subjects were re-evaluated. Among Sardinian immigrants, the prevalence of type 1 diabetes was 0.9%, while in the offspring group, the prevalence was 0.4%. After removing type 1 diabetic patients, the GADA prevalence was 2.4% in the immigrant group and 3.8% among their offspring. Among Sardin...
In the Sardinian population a very high incidence of insulindependent diabetes mellitus (IDDM) an... more In the Sardinian population a very high incidence of insulindependent diabetes mellitus (IDDM) and the lack of HLA-DR2 protective effect due to the high-frequency of the A2, Cw7, B17, 3F31, DR2, DQwl extended haplotype has been reported. This haplotype, carrying a Serine at position 57 of the DQB1*0502 allele, has been previously reported to be underrepresented in patients when compared to controls. In order to provide an explanation for this finding, we defined by RFLP analysis the HLA haplotype of 45 Sardinian IDDM patients and 49 controls. All DR-2DQw1 subjects were molecularly characterized at the HLA DQA and DQB loci. All DR2-positive patients and the vast majority of the DR2-positive controls had the DQB 1*0502 allele at the DR2-linked DQBl locus, with no statistically significant difference between the two groups. All DQAl genes were the ones expected, with only two exceptions. Nine out of 10 of the DRZpositive patients were compound heterozygotes for DQB 1 *020 1 /DQBl*O502 alleles; only this allele combination was significantly increased (p< 0.0003). Our data suggests that a) the DQB1*0502 allele is neutral for IDDM development and b) the susceptibility to IDDM in our DR2-positive patients is related to the compound hetrozygous state between the neutral DQAl*0102/DQB1*0502 and the I susceptibility DQA1*0501 /DQB1*0201 alleles.
The analysis of variation of risk for a given disease in space and time is a key issue in descrip... more The analysis of variation of risk for a given disease in space and time is a key issue in descriptive epidemiology. When the data are scarce, maximum likelihood estimates of the area‐specific risk and of its linear time‐trend can be seriously affected by random variation. In this paper, we propose a Bayesian model in which both area‐specific intercept and trend are modelled as random effects and correlation between them is allowed for. This model is an extension of that originally proposed for disease mapping. It is illustrated by the analysis of the cumulative prevalence of insulin dependent diabetes mellitus as observed at the military examination of 18‐year‐old conscripts born in Sardinia during the period 1936–1971. Data concerning the genetic differentiation of the Sardinian population are used to interpret the results.
approach to study the temporal trend and the geographical variation in the risk of type 1 diabete... more approach to study the temporal trend and the geographical variation in the risk of type 1 diabetes. The Sardinian Conscript Type 1 Diabetes Registry.
In 102 insulin-dependent diabetic patients without retinopathy and with visual acuity 20/20, the ... more In 102 insulin-dependent diabetic patients without retinopathy and with visual acuity 20/20, the Farnsworth-Munsell 100-Hue test was performed, and glycosylated hemoglobin (GlHb) levels were determined. In 70% of the patients, a dyschromatopsia in the yellow-blue axis (tritanopia) was found. No correlation existed between duration of diabetes and tritanopia. On the other hand, the degree of this visual defect was positively correlated with GlHb levels. Thus, dyschromatopsia might be associated with poor metabolic control. It is suggested that dyschromatopsia is a consequence of hypoxia at the neuroepithelial level. The high levels of GlHb could be a contributory cause of hypoxia by reduction of both oxygen release capacity and erythrocyte deformability.
BackgroundA high frequency of blue eyes and fair skin are reported in northern European Caucasian... more BackgroundA high frequency of blue eyes and fair skin are reported in northern European Caucasians with type 1 diabetes (T1D). Also there is an inverse relationship between latitude and T1D incidence. We determined whether iris colour and skin pigmentation are risk factors in a Caucasian population living in two Mediterranean regions located at the same latitude with higher ultraviolet B irradiance, but with different T1D incidence.MethodsWe studied iris colour in 281 consecutive subjects with T1D and 298 controls. Skin type was evaluated by melanin quantification.ResultsIn Lazio, blue eyes and fair skin type are significantly more common in T1D subjects than in controls (21 versus 9%, p = 0.002; 50 versus 35%, p < 0.001, respectively). In Sardinia, the frequency of blue eyes in T1D subjects is twice that in controls (5.8 versus 2.6% and significantly higher when compared to the expected calculated frequency in the entire population). By logistic regression analysis, only blue ey...
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Papers by Marco Songini