M. Serrano Ríos

Relationship between obesity and the increased risk of major complications in non-insulin-dependent diabetes mellitus

Obesity and non‐insulin‐dependent diabetes mellitus (NIDDM) are closely linked. They frequently occur together in patients, and body mass index (BMI) is the strongest risk factor for the development of NIDDM. Both obesity and NIDDM are also major causes of morbidity and mortality from atherogenic macrovascular disease, and they are independent risk factors for coronary heart disease. The risk of developing NIDDM and cardiovascular disease is affected by the regional distribution of body fat. Visceral obesity is associated with a higher degree of risk than peripheral obesity. The metabolic and circulatory changes associated with visceral obesity lead to the development of insulin resistance and increased lipoprotein synthesis. For example, the change in the population profile of lipoproteins in the blood, and alterations in the levels of oxidative stress lead to an increased cardiovascular and macrovascular risk. The changes in lipid metabolism also affect haemorrheological function. They have been linked to decreased fibrinolysis (a serious cardiovascular risk factor) through elevated levels of plasminogen activator inhibitor factor, high blood viscosity, and increased erythrocyte aggregability. Increased BMI also appears to be associated with endothelial dysfunction, which is a major factor in atheroma plaque formation and development of thrombosis. Visceral obesity therefore adds a significant burden to the already increased cardiovascular risk inherent in NIDDM. However, even moderate weight loss may successfully reverse the majority of changes seen with visceral obesity.

Incidence of Type 1 (insulin-dependent) diabetes mellitus in subjects 0–14 years of age in the Comunidad of Madrid, Spain

SummaryA retrospective, population-based registry was established in the Comunidad of Madrid, Spain (total population: 4,780,572; under age 15: 1,105,243) to investigate the epidemiology of Type 1 (insulin-dependent) diabetes mellitus. Included were all cases diagnosed with diabetes between 1985 and 1988, with age onset less than 15 years, and using insulin at discharge from hospital. Using the capture-recapture method employing hospital records as the primary source and membership files of the Spanish Diabetic Association as the secondary source, the ascertainment was 90%. The overall annual incidence was estimated to be 11.3/100,000 (Poisson 95% confidence interval: 10.3–12.4). There was no temporal increase in incidence, nor was there a significant sex difference in incidence rates, either overall or by year. The seasonal onset pattern showed the highest incidence in winter (December–February) and lowest in summer (June–August) (r=7.36, p<0.05). The age-adjusted (world standard) incidence of 10.9/100,000 was inconsistent with the hypothesis of a north-south gradient in diabetes risk.

Criterios de clasificación y significación clínica del síndrome metabólico

El sindrome metabolico (SM) es una situacion clinica multifactorial (genes y ambiente) cuya prevalencia e incidencia han aumentado notablemente en los ultimos 5 anos en paralelo con las de la diabetes mellitus (DM) tipo 2, obesidad visceral («diabesidad») y enfermedad cardiovascular. Es en los paises desarrollados donde estan proliferando con mas fuerza habitos dieteticos y de vida poco saludables (dieta rica en grasas saturadas, ingesta excesiva de alcohol, tabaquismo e inactividad entre otros). En estas circunstancias han surgido criterios de definicion del SM impulsados por diversas sociedades cientificas. Los mas recientes son faciles de aplicar en la practica clinica, pero difieren en determinados subgrupos poblacionales, por lo que todavia es necesario un consenso que defina unos criterios universalmente aceptados.

Diabetes mellitus. Concepto, clasificación y mecanismos etiopatogénicos

Concepto y clasificacion. La diabetes mellitus es un conjunto heterogeneo de sindromes hiperglucemiantes, resultado de un defecto de funcion de la celula s pancreatica y/o disminucion de la sensibilidad a la insulina en tejidos diana. Se ha clasificado en cuatro grupos (1997): tipos 1 y 2, gestacional y un ultimo grupo muy amplio con formas en general poco frecuentes. Entre el 10% y el 15% de los diabeticos adultos tienen un patron LADA (diabetes autoinmune del adulto). En Espana la prevalencia global se situa entre el 2,4% y el 7,8%. Etiopatogenia. La genetica, los fenomenos autoinmunes, entre los que cabe destacar los autoanticuerpos-anticelulas de islote, antiinsulina, anti-GAD e IA-2, y los factores ambientales como la dieta y actividad fisica estan entre las causas mas relevantes.

PREVALENCE, TREATMENT AND ASSOCIATED FACTORS OF HYPERTENSION IN URBAN AND RURAL AREAS OF SPAIN

Objective: To study the prevalence and related factors of hypertensive subjects according to the resident area (rural vs. urban) in two population-based studies from Spain: Variability of Insulin with Visceral Adiposity (VIVA) and Segovia Insulin Resistance Study (SIRS). Design and method: Cross-sectional survey. 5,941 males and non-pregnant females (54%) aged 35 to 74 years old, from a targeted population of 496,674 subjects from 21 small and middle-sized towns across Spain were invited to participate. Exclusion criteria: (1)Type 1 diabetes mellitus, (2)Heart failure or hepatic insufficiency, (3)Surgery in the previous year, (4)Abdominal wall hernias but for inguinal hernia, (5)Weight loss or gain > 5 kg in the previous six months, (6)Subjects living in nursing homes/hospices/hospitalized/institutionalized, (7)Pregnancy or delivery in the previous year. Medical questionnaires were administered as well as anthropometrics measured, using standardized protocols. Hypertension was diagnosed in pharmacology treated subjects or > 140/90 mmHg of blood pressure (BP). For type 2 diabetes mellitus subjects, hypertension was defined as BP > 140/85 mm Hg. Information on educational status, social class, smoking habit and alcohol intake was obtained. Results: 3,816 subjects were included. Prevalence of diagnosed hypertension was higher in women and showed no differences according to the living area (men: urban 21,88%vs. rural 21,92%, p = 0,986; women: urban 28,73%vs. 30,01%, p = 0,540). Prevalence of undiagnosed hypertension also increased with age and was higher in urban vs. rural population aged 46–60 years old (19.85%vs 14.18%, p = 0.018). Women living in rural areas and men with secondary or tertiary education levels have a lower probability of being BP uncontrolled (OR (95% CI): 0.501 (0.258–0.970)/p = 0,040, 0.245 (0.092–0.654)/p = 0.005 and 0.156 (0.044–0.549)/p = 0.004 respectively). Urban young men (31–45 years) and medium aged women (46–60 years) are worse BP controlled than their rural counterparts (41.30% vs. 65.79%/p = 0.025 and 53.27% vs. 35.24%/p = 0.002 respectively). Figure. No caption available. Conclusions: Women living in rural areas of Spain and men with secondary or tertiary education levels have a higher probability of being BP controlled. Urban young men (31–45 years) and medium aged women (46–60 years) are worse BP controlled than their rural counterparts. The prevalence of diagnosed hypertension increases with age, with no differences according to areas.

Pancreatic A and B cell hyperfunction in the mendenhall syndrome

SummaryA 16-year-old boy with persistent hyperglycaemia (approximately 16 mmol/l in the fasting state) and acanthosis nigricans had insulin resistance and received daily up to 2 800 U of short-acting, soluble, highly purified porcine insulin. The number and affinity of insulin receptors were markedly decreased. No significant insulin binding to IgG could be detected. Immunoreactive insulin varied between 1344 and 2400 mU/l. Endogenous insulin secretion and proinsulin levels were grossly elevated in the fasting state (C-peptide 2.2–3.5 pmol/ml; proinsulin approximately 1 pmol/ml). After an oral glucose tolerance test and intravenous arginine infusion, B cell hypersecretion was confirmed. The molar ratio of C-peptide to immunoreactive insulin, normally approximately 7, was about 0.3, clearly indicating that most of the immunoreactive insulin was exogenous. The molar ratio of proinsulin to C-peptide, which is about 0.05 in fasting control subjects, was 0.23–0.45, clearly showing that too high a proportion of proinsulin was being secreted. This may indicate that the constant hyperstimulation of the B cell leads to reduced conversion of proinsulin to insulin. Immunoreactive glucagon levels were within normal limits fasting but were above normal after intravenous arginine infusion. Thus, in this case of diabetes with acanthosis nigricans, the severe insulin resistance, probably caused by a receptor defect, was associated with markedly increased B cell function.

MORBIDITY AND MORTALITY IN A COHORT FROM CENTRAL SPAIN. THE SEGOVIA CARDIOVASCULAR DISEASE RISK STUDY

Objective: To describe the cause-specific morbidity and mortality in a follow-up period of ten years in a previously well characterized population based cohort. Design and method: Prospective population-based follow-up survey of 900 subjects recruited in 2001–2003 (aged 35–74 years) in the province of Segovia (Autonomous Community of Castilla y León, Spain). Health status was checked through medical records. Subjects were also invited to a new clinical interview. End-points: diagnosis of cardiovascular disease, neoplasms or other major diseases or death according to the International Statistical Classification of Diseases and Related Health Problems (ICD) 10th revision. Figure. No caption available. Results: Total mortality incidence was 7,12 % after a follow-up of 10,7 years. Main causes of death: neoplasms (50 %) and cardiovascular events (17.19 %). Morbidity: 10,79 % of subjects developed a cardiovascular event, being cerebrovascular disease the leading events cause (37 up to 112 events, 33.04 %). 118 (13.13 %) subjects developed a neoplasia [most frequent neoplasms were of skin (22.13 %) and gastrointestinal tract (17.21 %) origins]. Conclusions: Neoplasms are the main cause of death in middle aged and elderly subjects followed by cardiovascular disease. Considering both sexes, the most frequent diagnosed neoplasms were those of skin origin followed by gastrointestinal neoplasms. In this cohort, cerebrovascular disease was the most frequent cardiovascular event.

Hypertension in Type 2 Diabetes Mellitus

Type 2 Diabetes Mellitus (DM) is a heterogeneous collection of hyperglycaemic syndromes due to a variable combination of two basic physiopathological disturbances: A defective beta cell function and a decreased insulin sensitivity (insulin resistance) at specific target tissues: skeletal muscle, adipocytes. Type 2 DM, the most common form of Diabetes (over 90% of all cases) has become, as it has been Type 1 DM, a global problem with the characteristics of a worldwide epidemic due to the worrying increase in prevalence in the last 10 years. It has been estimated (Amos et al. 1997) that for year 2010 there will be over 221 million people affected with Type 2 DM as compared to the existing 124 millions in 1997. India, Pakistan, Africa, Asia and Latin America will be the hardest hit countries by this epidemic. The causes of Type 2 DM, and hence of the current increase in prevalence are many, including a complex interplay between a poligenic background, — likewise variable among different ethnic groups —, and a vast array of environmental factors related to inappropriate western-like (“cocacolonization”) lifestyle: excessive caloric intake, lack of physical activity, diet rich in refined foods and poor in fibre; and often an excessive alcohol intake. A major outcome of these factors is also the parallel emergence of a “bad” companion of Type 2 DM: obesity. Of major relevance is the central or visceral type of obesity, a condition typically promoting insulin resistance (IR) and the clustering of many metabolic and non-metabolic disturbances that integrate the so-called insulin resistance syndrome X or metabolic syndrome X, originally described by G. M. Reaven (Reaven 1988, Reaven 1999) and others. This metabolic syndrome is a high-risk situation for the development of macrovascular (atherosclerosis) disease and its consequences.