Sergio Valdés

Evolución de la prevalencia de la diabetes tipo 2 en población adulta española

La diabetes mellitus tipo 2 ha sido catalogada como la epidemia del siglo XXI tanto por su creciente magnitud como por su impacto en la enfermedad cardiovascular, primera causa de mortalidad en las sociedades desarrolladas. En esta revision analizamos la evolucion de la prevalencia de la diabetes en Espana en los ultimos anos, basandonos en los distintos estudios transversales realizados. Segun este analisis, las estimaciones previas han sido superadas, y actualmente se puede estimar que entre el 10 y el 15% de la poblacion adulta espanola tiene diabetes. Varios factores, como el cambio de criterios diagnosticos, el envejecimiento de la poblacion, la menor mortalidad de los diabeticos o un verdadero aumento de la incidencia, han podido influir en este fenomeno.

Population-Based Incidence of Type 2 Diabetes in Northern Spain: The Asturias Study

OBJECTIVE—The aim of this study was to define the incidence of type 2 diabetes in a low-risk Caucasian population in northern Spain and its association with various risk factors. RESEARCH DESIGN AND METHODS—The Asturias Study is a prospective, population-based survey of diabetes and cardiovascular risk factors. The baseline examination was carried out during 1998–1999 when 1,034 individuals, aged 30–75 years, were randomly selected to determine the prevalence of type 2 diabetes and pre-diabetes in the Principality of Asturias (northern Spain). In 2004–2005, these same subjects were invited for a follow-up examination; 700 participated. This study includes only those individuals who did not have diabetes at baseline. We used the World Health Organization 1999 criteria to classify glucose metabolism at both baseline and follow-up. RESULTS—The incidence of diabetes adjusted for the age and sex structure of Asturias was 10.8 cases/1,000 person-years (95% CI 8.1–14.8). The incidence rates were 5 cases/1,000 person-years in individuals with normoglycemia, 21 cases/1,000 person-years in individuals with isolated impaired glucose tolerance (IGT), 34.7 cases/1,000 person-years in individuals with isolated impaired fasting glucose (IFG), and 95.2 cases/1,000 person-years in individuals with combined IFG-IGT. Stepwise multiple logistic regression analysis showed that, together with fasting plasma glucose (FPG) and 2-h plasma glucose, which were the strongest predictors of diabetes, triglycerides and BMI were also independently associated with progression to diabetes. CONCLUSIONS—In this 6-year prospective population-based study, we found an incidence of type 2 diabetes of 10.8 cases/1,000 person-years. Both FPG and 2-h plasma glucose were strongly predictive of diabetes, and their effect was additive.

Incidence of type 2 diabetes in southern Spain (Pizarra Study)

Background  Few European studies have used an oral glucose tolerance test (OGTT) to examine the incidence of type 2 diabetes. We determined the incidence of impaired fasting glucose (IFG), impaired glucose tolerance (IGT) and type 2 diabetes in a population from southern Spain.

Vitamin D deficiency in Spain: a population-based cohort study

Background:Vitamin D deficiency is common worldwide. No homogenous reference values have yet been established and no studies of values have been conducted in Spain involving a large number of participants.Objective:To study the population concentrations of vitamin D in a representative sample of the Spanish population.Subjects/Methods:The study involved two cohorts from Spain, the Asturias study and the Pizarra study, which are two prospective, population-based studies involving 2260 participants. In 1262 subjects (age: 20–83 years) we studied 25-hydroxyvitamin D, intact parathyroid hormone (iPTH), calcium, phosphorus and creatinine.Results:The median population values of 25-hydroxyvitamin D and iPTH were 22.46 ng/ml and 42.29 pg/ml, respectively. The values of 25-hydroxyvitamin D were significantly higher in summer and correlated with age (β=−0.05±0.01, P<0.0001), creatinine (β=6.42±1.17, P<0.0001) and iPTH (−0.07±0.01, P<0.0001), but not with calcium, phosphorus or sex. The increase in iPTH with age was seen whatever the values of 25-hydroxyvitamin D, and was greater in the older persons. The concentration of iPTH rose continuously with effect from 25-hydroxyvitamin D values below ≈30 ng/ml. Values above ≈35 ng/ml were associated with a significantly lower concentration of iPTH.Conclusions:One-third (33.9%) of the Spanish population may be at risk for Vitamin D deficiency. The 25-hydroxyvitamin D values above 30 ng/ml can safely discard ‘hyper PTH’. The increase in iPTH concentration is greater in older persons for similar values of 25-hydroxyvitamin D.

Methylation levels of the SCD1 gene promoter and LINE-1 repeat region are associated with weight change: An intervention study

SCOPE Epigenetic processes may be affected by environmental factors. DNA methylation measured in LINE-1 elements (LINE-1, long interspersed nucleotide element-1) correlates with LINE-1 DNA methylation. Variations in stearoyl CoA desaturase (SCD) activity (a key enzyme in the fatty acid metabolism) may be involved in various processes that can lead to diseases such as obesity. We evaluated whether changes in diet after a nutritional intervention would be associated with changes in LINE-1 DNA methylation and/or specific methylation of SCD1 gene promoter. METHODS AND RESULTS DESIGN Prospective cohort intervention study with a control group. We recorded phenotypic, anthropometric, biochemical, and nutritional information at baseline and 1 year later. DNA methylation was quantified by pyrosequencing. LINE-1 DNA methylation and SCD1 gene promoter methylation levels were similar at the beginning of the study in both populations, whereas after a year these levels were higher in the control group (p < 0.001). In the intervention group, those subjects who lost weight showed higher levels of SCD1 gene promoter methylation after the intervention. Subjects with lower adherence to a Mediterranean diet experienced larger changes in LINE-1 methylation. CONCLUSION DNA methylation levels were associated with weight change and with adherence to a Mediterranean diet.

Iodine intake in the adult population. Di@bet.es study

BACKGROUND & AIMS To date no nation-wide study has yet been undertaken in Spain to estimate the iodine deficiency. The aim was to evaluate iodine intake and its conditioning factors in a representative sample of the whole adult population. METHODS The Di@bet.es Study is a national, cross-sectional, population-based survey conducted in 2009-2010 in Spain. RESULTS The median urinary iodine (UI) was 117.2 μg/L. Iodized salt (IS) was consumed by 43.9% of the population. The median UI in those who consumed IS and in those who did not consume IS was 131.1 and 110.8 μg/L respectively (p<0.0001). The likelihood of having UI levels above 100 μg/L was significantly associated with the intake of IS (OR=1.47) and milk at least once a day (OR=1.22). Within each individual autonomous communities, the median UI levels in those who consumed IS correlated significantly with the median levels of those who did not consume IS (r=0.76, p=0.001). CONCLUSIONS Though strictly speaking, Spain should be considered within the category of a country having an adequate iodine intake, the current value is too close to the cut point and does not guarantee that those groups with a greater need for iodine will have the required intake of iodine.

Surfactant Protein D, a Marker of Lung Innate Immunity, Is Positively Associated With Insulin Sensitivity

OBJECTIVE Impaired lung function and innate immunity have both attracted growing interest as a potentially novel risk factor for glucose intolerance, insulin resistance, and type 2 diabetes. We aimed to evaluate whether surfactant protein D (SP-D), a lung-derived innate immune protein, was behind these associations. RESEARCH DESIGN AND METHODS Serum SP-D was evaluated in four different cohorts. The cross-sectional associations between SP-D and metabolic and inflammatory parameters were evaluated in two cohorts, the cross-sectional relationship with lung function in one cohort, and the longitudinal effects of weight loss on fasting and circadian rhythm of serum SP-D and cortisol concentrations in one prospective cohort. RESULTS In the cross-sectional studies, serum SP-D concentration was significantly decreased in subjects with obesity and type 2 diabetes (P = 0.005) and was negatively associated with fasting and postload serum glucose. SP-D was also associated with A1C, serum lipids, insulin sensitivity, inflammatory parameters, and plasma insulinase activity. Smoking subjects with normal glucose tolerance, but not smoking patients with type 2 diabetes, showed significantly higher serum SP-D concentration than nonsmokers. Serum SP-D concentration correlated positively with end-tidal carbon dioxide tension (r = 0.54, P = 0.034). In the longitudinal study, fasting serum SP-D concentration decreased significantly after weight loss (P = 0.02). Moreover, the main components of cortisol and SP-D rhythms became synchronous after weight loss. CONCLUSIONS These findings suggest that lung innate immunity, as inferred from circulating SP-D concentrations, is at the cross-roads of inflammation, obesity, and insulin resistance.

Type 2 diabetes mellitus in relation to global LINE-1 DNA methylation in peripheral blood: A cohort study

In the last years, epigenetic processes have emerged as a promising area of complex diseases research. DNA methylation measured in Long Interspersed Nucleotide Element 1 (LINE-1) sequences has been considered a surrogate marker for global genome methylation. New findings have suggested the potential involvement of epigenetic mechanisms in Type 2 diabetes (T2DM) as a crucial interface between the effects of genetic predisposition and environmental influences. Our study evaluated whether global DNA methylation predicted increased risk from T2DM or other carbohydrate metabolism disorders in a cohort study. We used a prospective cohort intervention study and a control group. We collected phenotypic, anthropometric, biochemical, and nutritional information from all subjects. Global LINE-1 DNA methylation was quantified by pyrosequencing technology. Subjects that did not improve their carbohydrate metabolism status showed lower levels of global LINE-1 DNA methylation (63.9 ± 1.7 vs. 64.7 ± 2.4) and they practiced less intense physical activity (5.8% vs. 21.5%). Logistic regression analyses showed a significant association between LINE-1 DNA methylation and metabolic status after adjustment for sex, age, BMI, and physical activity. Our study showed that lower LINE-1 DNA methylation levels were associated with a higher risk metabolic status worsening, independent of other classic risk factors. This finding highlights the potential role for epigenetic biomarkers as predictors of T2DM risk or other related metabolic disorders.

Thyroid hormone levels predict the change in body weight: a prospective study.

Eur J Clin Invest 2011; 41 (11): 1202–1209

HbA1c in the prediction of type 2 diabetes compared with fasting and 2-h post-challenge plasma glucose: The Asturias study (1998–2005)

AIM Fasting plasma glucose (FPG) and the 2-h post-challenge plasma glucose (2hPG) are commonly used to identify those at risk of type 2 diabetes. However, the role of HbA(1c) in this prediction has still not been ascertained. METHODS The Asturias study is a prospective population-based survey of diabetes and cardiovascular risk factors. Baseline examination, carried out during 1998-1999, involved 1034 individuals, aged 30-75 years, randomly selected to determine the prevalence of type 2 diabetes and prediabetes in the principality of Asturias (northern Spain). In 2004-2005, these same subjects were invited to a follow-up examination, and 700 participated. The present study includes only those who did not have diabetes at baseline. All participants with no known diabetes underwent an OGTT. Baseline HbA(1c) levels were measured by HPLC. RESULTS Diabetes had developed in 44 participants at the time of follow-up. Quartiles of baseline HbA(1c) values were 3.4-4.8 (Q1), 4.9-5.1 (Q2), 5.2-5.4 (Q3) and 5.5-6.9 (Q4), and the incidence rates of diabetes by quartiles were 1.0 (0.1-7.1), 4.0 (1.5-10.7), 7.9 (4.0-15.9) and 32.6 (22.9-46.4) cases/1000 person-years, respectively. ROC curve analysis comparing HbA(1c), FPG and 2hPG in the prediction of diabetes showed areas under the curve (ROC-AUC) of 0.80 (0.74-0.86), 0.83 (0.77-0.90) and 0.79 (0.72-0.87), respectively. The combination of FPG and HbA(1c) had the best predictive performance with an ROC-AUC of 0.88 (0.82-0.93). CONCLUSION Our study indicates that HbA(1c) is strongly predictive of new-onset diabetes in this northern Spanish population, and was similar to FPG and 2hPG in predictive capability. Also, the combined measurement of FPG and HbA(1c) improved their individual predictive performance.