F. Soriguer

Prevalence of diabetes mellitus and impaired glucose regulation in Spain: the Di@bet.es Study.

Aims/hypothesisThe Di@bet.es Study is the first national study in Spain to examine the prevalence of diabetes and impaired glucose regulation.MethodsA population-based, cross-sectional, cluster sampling study was carried out, with target population being the entire Spanish population. Five thousand and seventy-two participants in 100 clusters (health centres or the equivalent in each region) were randomly selected with a probability proportional to population size. Participation rate was 55.8%. Study variables were a clinical and demographic structured survey, lifestyle survey, physical examination (weight, height, BMI, waist and hip circumference, blood pressure) and OGTT (75xa0g).ResultsAlmost 30% of the study population had some carbohydrate disturbance. The overall prevalence of diabetes mellitus adjusted for age and sex was 13.8% (95% CI 12.8, 14.7%), of which about half had unknown diabetes: 6.0% (95% CI 5.4, 6.7%). The age- and sex-adjusted prevalence rates of isolated impaired fasting glucose (IFG), isolated impaired glucose tolerance (IGT) and combined IFG–IGT were 3.4% (95% CI 2.9, 4.0%), 9.2% (95% CI 8.2, 10.2%) and 2.2% (95% CI 1.7, 2.7%), respectively. The prevalence of diabetes and impaired glucose regulation increased significantly with age (pu2009<u20090.0001), and was higher in men than in women (pu2009<u20090.001).Conclusions/interpretationThe Di@bet.es Study shows, for the first time, the prevalence rates of diabetes and impaired glucose regulation in a representative sample of the Spanish population.

Iodine concentration in cow’s milk and its relation with urinary iodine concentrations in the population

BACKGROUND & AIMSnThe importance of milk intake to the supply of dietary iodine is not fully known. We therefore undertook a study in Spain of the iodine concentration in cows milk and the impact of the frequency of milk consumption on urinary iodine concentrations in three study populations.nnnMETHODSnWe studied the iodine concentration in 362 samples of milk from 45 commercial brands and compared it with the milk iodine status in studies undertaken 17 years earlier. The epidemiologic studies were performed in three different places in the south of Spain: two in school-age children (Nxa0=xa0757 and Nxa0=xa01205 children) and one in adults (Nxa0=xa01051). A milk consumption questionnaire was given and urinary iodine concentrations measured.nnnRESULTSnThe mean concentration of iodine in the milk rose from 1991 (117xa0±xa037xa0μg/L) to 2008 (259xa0±xa058xa0μg/L) (Pxa0<xa00.001). The iodine concentration was greater in skimmed milk (273xa0±xa052xa0μg/L) than in semi-skimmed milk (254xa0±xa057xa0μg/L) or whole milk (251xa0±xa061xa0μg/L) (Pxa0<xa00.0001). The winter samples had a greater concentration of iodine (270xa0±xa055xa0μg/L) than the summer samples (247xa0±xa058xa0μg/L) (Pxa0<xa00.0001), independently of the type of milk. The urinary iodine concentrations in all three epidemiologic studies were significantly associated with the frequency of milk intake.nnnCONCLUSIONSnThe concentration of iodine in cows milk has risen over recent years, and it is higher in skimmed milk. The results also show that cows milk is a relevant source of dietary iodine.

Prevalence of obesity in south-east Spain and its relation with social and health factors

Recent studies have confirmed important regional differences in the prevalence of obesity, as well as a tendency for this prevalence to increase. Determination of the social factors involved in obesity may be very useful to design intervention and prevention strategies. This transverse study was undertaken in Pizarra (Malaga, Spain) from a random sample of the population between 18 and 65 years of age (n = 1226). All participants were interviewed and given a physical examination. Standardized anthropometrical measurements were made, and a baseline blood sample was taken after an oral glucose tolerance test. The overall prevalence of obesity (BMI > 30 kg/m2) was 28.8%. This figure increased continuously from 10% in the group aged 18–25 years to above 50% in the groups aged over 55 years. This prevalence is higher than that reported in most other studies in Spain. The obese persons ate differently, at least from a qualitative viewpoint, probably more saturated fats and fewer unsaturated fats, and had a different behaviour concerning alcohol and smoking. Marital status was related with the rate of obesity, and the close relation between the level of education and the risk of obesity was confirmed (OR = 3.8 for being obese and having no education compared to having university studies). The most important consequence of the study was that all these factors are potentially modifiable and preventable. An increased level of general education in the population may well contribute decisively to a reduction in the prevalence of obesity.

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

Backgroundu2002 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 22.46u2009ng/ml and 42.29u2009pg/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 ≈30u2009ng/ml. Values above ≈35u2009ng/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 30u2009ng/ml can safely discard ‘hyper PTH’. The increase in iPTH concentration is greater in older persons for similar values of 25-hydroxyvitamin D.

Hypovitaminosis D and incidence of obesity: a prospective study

The aim of this study was to assess the relationship between obesity and vitamin D status cross-sectionally, the relationship between obesity and the incidence of hypovitaminosis D prospectively and inversely the relationship between vitamin D status and incidence of obesity in a population-based cohort study in Spain. At baseline (1996–1998), 1226 subjects were evaluated and follow-up assessments were performed in 2002–2004 and 2005–2007, participants undergoing an interview and clinical examination with an oral glucose tolerance test. At the second visit, 25-hydroxyvitamin D and intact parathyroid hormone concentrations were also measured. Prevalence of obesity at the three visits was 28.1, 36.2 and 39.5%, respectively. The prevalence of vitamin D deficiency (25-hydroxyvitamin D ⩽20u2009ng/ml (⩽50u2009nmol/l)) was 34.7%. Neither obesity at baseline (OR=0.98, 95% CI: 0.69-1.40, P=0.93) nor the development of obesity between baseline and the second evaluation (OR=0.80, 95% CI: 0.48–1.33, P=0.39) were significantly associated with vitamin D status. In subjects who were non-obese (BMI <30u2009kg/m2) at the second evaluation, 25-hydroxyvitamin D values ⩽17u2009ng/ml (⩽42.5u2009nmol/l) were significantly associated with an increased risk of developing obesity in the next 4 years (OR=2.35, 95% CI: 1.03–5.4, P=0.040 after diverse adjustments). We conclude that vitamin D deficiency is associated with an increased risk of developing obesity.

Stearoyl-CoA desaturase-1 is associated with insulin resistance in morbidly obese subjects.

Animal studies have revealed the association between stearoyl-CoA desaturase 1 (SCD1) and obesity and insulin resistance. However, only a few studies have been undertaken in humans. We studied SCD1 in visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) from morbidly obese patients and their association with insulin resistance, sterol regulatory element binding protein-1 (SREBP-1) and ATPase p97, proteins involved in SCD1 synthesis and degradation. The insulin resistance was calculated in 40 morbidly obese patients and 11 overweight controls. Measurements were made of VAT and SAT SCD1, SREBP-1 and ATPase p97 mRNA expression and protein levels. VAT and SAT SCD1 mRNA expression levels in the morbidly obese patients were significantly lower than in the controls (P = 0.006), whereas SCD1 protein levels were significantly higher (P < 0.001). In the morbidly obese patients, the VAT SCD1 protein levels were decreased in patients with higher insulin resistance (P = 0.007). However, SAT SCD1 protein levels were increased in morbidly obese patients with higher insulin resistance (P < 0.05). Multiple linear regressions in the morbidly obese patients showed that the variable associated with the SCD1 protein levels in VAT was insulin resistance, and the variables associated with SCD1 protein levels in SAT were body mass index (BMI) and ATPase p97. In conclusion, these data suggest that the regulation of SCD1 is altered in individuals with morbid obesity and that the SCD1 protein has a different regulation in the two adipose tissues, as well as being closely linked to the degree of insulin resistance.

Dietary fatty acids and insulin secretion: a population-based study

Objective:Few epidemiological studies have examined the relationship of dietary fatty acids, especially MUFA, with the interrelation between insulin secretion and insulin resistance. We assessed the relation of dietary fatty acids with insulin secretion in a free-living population.Design and setting:This cross-sectional, population-based study was undertaken in Pizarra, a small town in Spain.Subjects and methods:Anthropometrical data were collected for 1226 persons selected randomly from the municipal census, 538 of whom (randomly chosen) were given a prospective, quantitative, 7-day nutritional questionnaire. The fatty acid composition of the serum phospholipids was used as a biological marker of the type of fat consumed. Beta-cell function (βCFI) and insulin-resistance index (IRI) were estimated by the Homeostasis Model Assessment.Results:To determine which factors influence the variability of the βCFI, we analyzed the variance of the βCFI according to sex, the presence of carbohydrate metabolism disorders and the different components of the diet, adjusting the models for age, body mass index (BMI) and IRI. The dietary MUFA and polyunsaturated fatty acids (PUFA) contributed to the variability of the βCFI, whereas only the proportion of serum phospholipid MUFA, but neither the saturated fatty acids nor the PUFA accounted for part of the variability of the βCFI in a multiple regression analysis.Conclusion:The results of this population-based study corroborate the results of other clinical and experimental studies suggesting a favorable relationship of MUFA with β-cell insulin secretion.Sponsorship:Fondo de Investigación Sanitaria, Junta de Andalucía and the Asociación Maimónides.

Vitamin D and incidence of diabetes: A prospective cohort study

BACKGROUND & AIMSnTo investigate the relationship between levels of 25-hydroxyvitamin D and the incidence of type 2 diabetes in a Spanish population.nnnMETHODSnWe undertook a population-based prospective study in a population from southern Spain. The first phase of the study (1996-1998) included 1226 individuals. Of this original cohort, 988 persons were reassessed in 2002-2004 and 961 in 2005-2007. Measurements were made of 25-hydroxyvitamin D and intact parathyroid hormone in 2002-2004 and an oral glucose tolerance test was done in three time points.nnnRESULTSnThe incidence of diabetes in subjects with 25-hydroxyvitamin D levels ≤ 18.5 ng/mL (percentile 25) was 12.4% vs 4.7% in subjects with levels >18.5 ng/mL. The likelihood of having diabetes during the four years of follow-up was significantly lower in the subjects with higher levels of 25-hydroxyvitamin D [OR = 0.17 (0.05-0.61)]. None of the subjects with levels higher than 30 ng/mL developed diabetes.nnnCONCLUSIONnIn this prospective study, we found a significant inverse association between serum 25-hydroxyvitamin D levels and the risk for type 2 diabetes in a population from the south of Spain.

Incidence of obesity is lower in persons who consume olive oil

We undertook a population-based cohort study in Pizarra (Spain). Anthropometric and nutritional variables were recorded for 613 persons. The type of fat used was determined by measurement of the fatty acids contained in cooking oil. Serum fatty acid was used as a biological marker of the type of fat consumed. Obesity incidence in persons who were not obese at baseline was greater in those who consumed sunflower oil (Group 1: 41.5 (95% CI, 25.4–67.8) cases per 1000 person-years) than in those who consumed olive oil or a mixture of oils (Group 2: 17.3 (95% CI, 11.6–25.8) cases per 1000 person-years). The risk of developing obesity over 6 years, adjusted for age, sex, physical activity, smoking, instruction level, energy intake and baseline BMI, was 2.3 (95% CI, 1.06–5.02) in group 1 compared with that in group 2. The increase in the prevalence of obesity in the free-living population is associated with the type of fatty acids in the diet.