Obesidad: concepto, clasificación y diagnóstico / Obesity: concept, classification and diagnosis

La obesidad es una enfermedad crónica que se caracteriza por un aumento de la masa grasa y en consecuencia por un aumento de peso. Existe, pues, un aumento de las reservas energéticas del organismo en forma de grasa. El término crónico se le aplica debido a que forma parte del grupo de enfermedades que no podemos curar con el arsenal terapéutico del que se dispone en la actualidad. Desde un punto de vista antropométrico, que es el habitualmente utilizado en clínica, se considera obesa a una persona con un Índice de Masa Corporal igual o superior a 30 kg/m2. Para poder valorar la obesidad se deben tener en cuenta no sólo los aspectos antropométricos sino también los posibles factores genéticos; hay que investigar las causas de la enfermedad y comprobar la posible existencia de complicaciones y enfermedades asociadas. El tratamiento siempre deberá ser personalizado y adaptado a las características y a las comorbilidades que presente el enfermo. Los criterios dominantes favorables a la intervención terapéutica en la obesidad se basan, especialmente, en la demostración de que con una pérdida moderada de peso corporal (5-10 por ciento) se puede conseguir una notable mejoría en la comorbilidad asociada a la obesidad y en la calidad de vida del paciente obeso (AU)

[Obesity: concept, classification and diagnosis]. / Obesidad: concepto, clasificación y diagnóstico.

Obesity is a chronic disease that is characterised by an increase of fat mass and as a result by an increase in weight. There is therefore an increase in the energy reserves of the organism in the form of fat. The term chronic is applied due to its forming part of the group of diseases that we are unable to cure with the therapeutic arsenal that is now available. From an anthropometric point of view, which is habitually used in the clinic, a person is considered to be obese with a Body Mass Index equal to or higher than 30 kg/m2. To be able to evaluate obesity account must be taken not only of the anthropometric aspects but also of the possible genetic factors; the causes of the disease must be studied and the possible existence of associated complications and diseases must be checked. Treatment must always be personalised and adapted to the characteristics and comorbidities presented by the patient. The dominant criteria favourable to therapeutic intervention in obesity are especially based on the demonstration that with a moderate loss of body weight (5-10 %) a notable improvement can be obtained in the comorbidity associated with obesity and in the quality of life of the obese patient.

Influence of sociodemographic factors in the prevalence of obesity in Spain. The SEEDO'97 Study.

OBJECTIVE: To analyse the influence of social and cultural factors in the prevalence of obesity in the Spanish adult population aged 25--60 y based on available population data. DESIGN: Pooled analysis of four cross-sectional nutrition surveys. SUBJECTS: A total of 5388 free-living subjects aged 25--60 y, respondents of the Nutritional Surveys carried out in four Spanish regions (Catalunya, Basque Country, Madrid and Valencia) from 1990 to 1994. The samples were pooled together and weighted to build a national random sample. MEASUREMENTS: Weight and height were measured on each individual by trained observers. Age, gender, educational level, occupation, habitat (rural/urban) and region were considered. Obesity was defined as body mass index > or = 30 kg/m(2). The protocol used in each survey was in accordance with the recommendations of the Spanish Society for the Study of Obesity (SEEDO). Logistic regression models were designed to analyse the influence of sociodemographic factors in the prevalence of obesity in men and women. RESULTS: The prevalence of obesity was higher in older age groups in men and women, odds ratio (OR) for every 10 y OR=1.40 (95% CI 1.39--1.41) for men and OR=1.86 (95% CI 1.85--1.87) for women. Logistic regression analysis adjusted for age showed higher obesity rates among low educated people, OR=1.80 (95% CI 1.78--1.81) in men and OR=2.36 (95% CI 2.29--2.42) in women (P<0.001). Among men the odds ratio for the prevalence of obesity in rural areas was OR=1.87 (95% CI 1.86--1.89), compared to cities. The geographical distribution showed higher obesity rates in the southeast. CONCLUSION: This study supports that obesity is a multifactorial problem. Older women with low educational level and low income seem to be the most susceptible group to weight gain. Therefore, Public Health Programs should consider this type of environmental factor when planning strategies aimed at preventing or reducing the problem of obesity in western societies.

Urinary free cortisol excretion pattern in morbid obese women.

The urinary excretion of free cortisol in a group of 10 control and 20 morbidly obese women was measured in all bladder voidings during 24 h. The data from obese women were measured under Hospital basal controlled conditions and after 3 days of very low calorie diet (VLCD, 1.9 MJ/d). The hourly cortisol excretion pattern was determined for each woman, and means of each group were computed in order to obtain a 24 h excretion pattern. In controls, the highest excretion rate was in the morning (8-9 h) and the lowest at 21-22 h. Inbasal conditions, the obese showed a similar but flatter pattern; the highest peak was also in the morning (9-10 h), but the lowest rate was between 21 and 24 h. The VLCD diet flattened the pattern even more, in away that no clear peak was observed from the early morning until the afternoon; however, the nadir coincided with that found in basal conditions. These patterns resulted in significant differences between VLCD, basal diet and control. The amount of free cortisol excreted was 93.0 +/- 6.9 nmol/ day in controls, 70.1 +/- 4.7 nmol/day in obese under basal conditions and 62.6 +/- 3.0 nmol/day when subjected to VLCD. The results presented are consistent with a lower overall cortisol secretion in the morbid obese women, which also show a narrower margin of variation in cortisol secretion than non-obese controls. The data also show the significant influence of dietary energy on the pattern of cortisol excretion in obese women.

[Hormonal alterations on young morbid obese women]. / Alteraciones hormonales en mujeres jóvenes con obesidad mórbida.

BACKGROUND: Human obesity is a widespread disease with considerable variability as to its severity, metabolic and endocrine manifestations and etiology. In the present study we have determined whether the alterations of uncomplicated severe obesity in adult young women affect with different intensity the circulating levels of hormones that have been postulated to intervene in the development and maintenance of obesity. SUBJECTS AND METHOD: Age-matched 20 morbidly obese (BMI 52.6 [8.3 SD] kg/m2) and 10 normal-weight control women (BMI 19.9 [2.1 SD] kg/m2)were studied and determined the basal circulating levels of hormones and proteins related with the control of body weight. RESULTS: Obese women showed higher concentrations of insulin and leptin, and lower of cortisol and cortisol-binding globulin (CBG). No significant differences were appreciated for free thyroxine, TSH, free and acylestrone and dehydroepiandrosterone-sulphate. CONCLUSIONS: The results suggest that morbid obesity implies the alteration of the main hormonal systems controlling the availability of energy and the response to external challenges, with the noteworthy exception of the thyroid. There were clear alterations of insulin and leptin,but cortisol changes could be more related to factors other than obesity. The lower than expected levels of acylestrone point to a possible deficit of this ponderostat signal in obese women. The relatively young age of the women in the study may account for the relative shallowness of the hormonal changes observed.

Short-term effects of a hypocaloric diet on nitrogen excretion in morbid obese women.

OBJECTIVE: To determine whether the daily pattern of urine excretion of N wastes is affected by obesity and very low-calorie diets (VLCD). DESIGN: The plasma amino acid, urea and other energy parameters, as well as the urinary excretion of total nitrogen, urea and creatinine were studied in obese and normal-weight women. The obese women's data were obtained under hospital basal controlled conditions (8.1 MJ/day) and after 3 days of VLCD diet (1.9 MJ/day) controls were studied only once (5.8 MJ/day). The hourly excretion patterns of total N, urea and creatinine were determined from the composition of each bladder voiding. SUBJECTS: Twenty morbidly obese and 10 age-matched normal-weight control women. RESULTS: Plasma amino acid levels were higher in obese women, which showed a limited ability to metabolize amino acid hydrocarbon skeletons. Neither differences in the patterns between groups nor total 24 h values for urine volume were found. Total N and urea excretion diminished under VLCD diet. Hourly creatinine excretion showed a flat pattern and was higher in obese women than in the controls, VLCD diet diminished the amount of creatinine excreted in 24 h. CONCLUSIONS: The early change in energy availability that the creatinine excretion figures reflect may result from the energy conservation mechanisms induced in response to energy restriction. The early onset of this effect (3 days, and the extent of decrease (approximately 19%) also suggest that the impact of VLCD on the muscle energy budget of the obese is more marked than usually assumed.

Diagnostic efficiency of serum IGF-I, IGF-binding protein-3 (IGFBP-3), IGF-I/IGFBP-3 molar ratio and urinary GH measurements in the diagnosis of adult GH deficiency: importance of an appropriate reference population.

OBJECTIVE: To analyse the diagnostic role of serum IGF-I, IGF-binding protein-3 (IGFBP-3), IGF-I/IGFBP-3 molar ratio and urinary GH (uGH) excretion in adult GH deficiency (GHD). DESIGN: Twenty-seven adults (age range: 18-71 years) with severe GHD, defined by a peak GH response to an insulin tolerance test below 3microg/l in patients with at least one additional pituitary hypofunction. Reference values were established from a selected age- and body mass index-matched population (154 healthy adults grouped in four age groups). METHODS: IGF-I and IGFBP-3 were measured by RIA (Nichols) and results expressed as standard deviation (s.d.) scores from our reference population and assay normative data (s.d. score Nichols). uGH was measured by IRMA. RESULTS: Within the control group, IGF-I, IGFBP-3, IGF-I/IGFBP-3 ratio standardisation regarding our control population and IGF-I with respect to the assay normative data resulted in disappearance of age-related differences. However, IGFBP-3 s.d. score Nichols resulted in mean values between +1.4 and +2.5 s.d. score. Greatest diagnostic efficiency was for IGF-I standardised with respect to our controls (97.2%), followed by s.d. score IGFBP-3 (92.9%). s.d. score IGF/IGFBP-3 ratio and uGH showed poor diagnostic efficiency. Any combination of at least two abnormal parameters raised specificity to 100%. IGF-I standardised with respect to assay reference (s.d. score Nichols) showed similar diagnostic value (95.0%) whereas IGFBP-3 showed low sensitivity (33. 3%). Within the GHD patients, those with three or more additional deficiencies had lower s.d. score IGF-I than those with only two or one. CONCLUSION: We underline the importance of an appropriate reference population for correct interpretation of GH secretion markers. Considering our results, specificity obtained with two simultaneous abnormal parameters when referred to an adequate reference population may add valuable information to alternative GH stimulation tests to confirm adult GHD.

Postpartum thyroiditis: epidemiology and clinical evolution in a nonselected population.

Postpartum thyroiditis (PPT) presents in approximately 5% of women. Its incidence, clinical characteristics, and evolution were studied in a nonselected population of Mediterranean women. Six hundred five healthy women, recruited between the 36th week of pregnancy and the 4th postpartum day, underwent initial clinical and biological evaluation and postpartum at 1 (n = 605), 3 (n = 552), 6 (n = 574), 9 (n = 431), and 12 (n = 444) months. PPT was diagnosed in women with transient hyperthyroidism between 1 and 3 months postpartum and/or hypothyroidism between 3 and 6 months postpartum. Permanent hypothyroidism was considered if it was overt and persisted one year after diagnosis. The incidence rate of PPT was 7.8%. Eighty-two percent of PPT patients had hormone abnormalities at the 6th month postpartum, 8.8% showed depression and 51% goiter. PPT was manifest as hyperthyroidism plus hypothyroidism in 35.5% of patients, because only transient hyperthyroidism in 22.2% and as hypothyroidism alone in 42.3%. Five patients with hypothyroidism during PPT (0.82% of the initial population, 11.1% of PPT patients, and 15.6% of hypothyroidism PPT patients) presented permanent hypothyroidism after a follow-up of 39.8 (4.2) months. PPT was found in 7.8% of general Mediterranean population. We recommend evaluation at the 6th postpartum month to diagnose the majority of PPT women and indefinite follow-up of hypothyroid PPT patients to detect permanent hypothyroidism.

La hora del relevo / Change of pace

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Meningococcal disease in a large urban population (Barcelona, 1987-1992): predictors of dismal prognosis. Barcelona Meningococcal Disease Surveillance Group.

CONTEXT: Studies on meningococcal disease in large urban communities have rarely been performed and are usually based on passive epidemiologic surveillance. Active surveillance may provide new insights. OBJECTIVES: To determine epidemiologic, clinical, and bacteriological characteristics and predictors of dismal prognosis (death and sequelae) in meningococcal disease. DESIGN: Prospective, population-based study. SETTING: All the acute care hospitals (n = 24) in Barcelona, Spain. PATIENT: The 643 patients whose conditions were diagnosed from 1987 through 1992 were detected by 2 active surveillance methods. OUTCOME MEASURES: Incidence and notification to Public Health Service. Clinical and bacteriological features were determined. Dismal prognosis predictors were determined by logistic regression. RESULTS: Average annual incidence was 6.41 per 100,000 inhabitants, with no clear trend of change (P = .08). Sensitivity of the Public Health Service surveillance system was 69.1%. Children younger than 10 years from the inner city were at higher risk than those from the highest income district (relative risk, 3.00; 95% confidence interval [CI], 1.84-5.06). Increasing annual incidence of serogroup C (0.82-1.29/100,000; P = .008) and decreasing incidence of serogroup B (5.11-2.82/100,000; P = .004) was noted. Average annual mortality was 0.40 per 100,000 inhabitants, while the annual average potential years of life lost was 18 per 100,000 inhabitants. Overall case-fatality rate was 6.4%. Independent predictors of death were hemorrhagic diathesis (odds ratio [OR], 63; 95% CI, 21-194), focal neurologic signs (OR, 10; 95% CI, 3-30), and age 60 years or older (OR, 6; 95% CI, 2-17), whereas preadmission antibiotic therapy was associated with favorable outcome (OR, 0.07; 95% CI, 0.02-0.3). Four percent of survivors presented with sequelae. Independent predictors of sequelae were hemorrhagic diathesis (OR, 21; 95% CI, 3-131), focal neurologic signs (OR, 16; 95% CI, 5-53), age 60 years or older (OR, 7; 95% CI, 2-26), and age between 15 and 59 years (OR, 5; 95% CI, 2-14), whereas preadmission antibiotic therapy had a protective effect (OR, 0.2; 95% CI, 0.04-0.5). CONCLUSIONS: Active epidemiologic surveillance significantly improved detection of cases and allowed us to observe that meningococcal disease still causes much morbidity and mortality, especially among children living in the inner city. Hemorrhagic diathesis, focal neurologic signs, and age were independent predictors of dismal prognosis, whereas preadmission antibiotic therapy had a protective effect.

Prospective study of community-acquired pneumonia of bacterial etiology in adults.

The aim of this study was to prospectively analyze the bacterial etiology of community-acquired pneumonia in adults in Spain. From May 1994 to February 1996, 392 episodes of CAP diagnosed in the emergency department of a 600-bed university hospital were studied. An etiological diagnosis based on noninvasive microbiological investigations was achieved in 228 cases (58%); 173 of these diagnoses were definitive and 55 probable. Streptococcus pneumoniae, which caused 23.9% of the episodes, was the predominant pathogen observed, followed by Chlamydia pneumoniae (13.5%) and Legionella pneumophila (12.5%). Other less frequent pathogens found were Haemophilus influenzae (2.3%), Pseudomonas aeruginosa (1.5%), Mycoplasma pneumoniae (1.3%), Coxiella burnetii (1%), Moraxella catarrhalis (2 cases), Nocardia spp. (2 cases), and Staphylococcus aureus (2 cases). Streptococcus pneumoniae was significantly more frequent in patients with underlying disease and/or age > or =60 years (28% vs. 13%, P = 0.002), while Legionella pneumophila was more frequent in patients below 60 years of age and without underlying disease (20% vs. 9%, P = 0.006). Likewise, Streptococcus pneumoniae and Legionella pneumophila were the most frequent etiologies in patients requiring admission to the intensive care unit, occurring in 29% and 26.3% of the patients, respectively. In addition to Streptococcus pneumoniae, other microorganisms such as Chlamydia pneumoniae and Legionella spp. should be seriously considered in adults with community-acquired pneumonia when initiating empiric treatment or ordering rapid diagnostic tests.

[Prevalence of obesity in Spain: the SEEDO'97 study. Spanish Collaborative Group for the Study of Obesity]. / Prevalencia de la obesidad en España: estudio SEEDO'97. Grupo Colaborativo Español para el Estudio de la Obesidad.

BACKGROUND: The weight distribution of a random sample of Spanish population aged 25-60 years is described. The prevalence of obesity and overweight is estimated by sex, age group and cultural level. SUBJECTS AND METHOD: Weight, height and waist to hip ratio (WHR) were measured on 5,388 subjects aged 25-60 yr who participated in population Nutritional surveys carried out in four Spanish autonomous regions (Cataluña, País Vasco, Madrid and Valencia) from 1989 to 1994. They were pooled together in order to build a national random sample. The sample was classified according to body mass index (BMI) (weight in kg/height in m2). Obesity was defined as BMI > or = 30 kg/m2. The prevalence of obesity by sex, age group and cultural level was estimated. Risk values for WHR were defined as WHR > 1 for men and WHR > 0.9 for women. RESULTS: The prevalence of obesity was 13.4%, 11.5% among men and 15.2% among women. Obesity increased with age in men and women, from 5.3% in the 25-34 yr group to 26.3% in the age group 55-60. Among those with a BMI > or = 30, 30.7% of men and 25.1% of women had also risk values for WHR. Educational level showed an inverse relationship with obesity, thus obesity was higher in less educated groups, particularly among women (p < 0.001). The geographical distribution of obesity showed a south-southeast trend, significant for males (p < 0.001). CONCLUSIONS: Prevalence of obesity in Spain was 13.4%, higher after 45 yr of age, particularly in women and less educated groups.

Growth hormone-binding protein directly depends on serum leptin levels in adults with different nutritional status.

The aim of this work was to assess the relationship between GH-binding protein (GHBP) and leptin. Both peptides are nutritionally regulated, but the recent implication of a role for leptin in the GH axis requires further study. To avoid the sexual dimorphism in leptin values, we performed leptin standardization according to gender (SD score-leptin). The relationship between SD score-leptin and GHBP was studied in 128 adults with different nutritional status [8 groups according to body mass index (BMI)], ranging from severely underweight anorexia nervosa to highly morbid obesity. Both GHBP and SD score-leptin significantly increased according to BMI within the range from 18-27 kg/m2, whereas no significant differences were found among underweight groups (BMI, < 18 kg/m2) or among obesity grades (BMI, > 27 kg/m2). We found a strong correlation between GHBP and SD score-leptin (r = 0.8; P < 0.0001). Multiple regression analysis revealed SD score-leptin to be a significant determinant of GHBP, accounting for 64% of the variation, whereas BMI did not contribute further to explaining changes in GHBP. This suggests a physiological pathway involving both GHBP (the soluble fraction of GH receptor) and leptin. Thus, we might speculate that leptin could be the signal that induces the related nutritional changes observed in GHBP/GH receptor expression.

Increased leptin production in vivo and insulin cleavage by the omental adipose tissue of morbidly obese patients.

OBJECTIVE: The aim of this investigation was to assess the insulin cleavage capacity in obese humans. Increased insulin degradation by visceral adipose tissue has previously been demonstrated in obese rats and could be interpreted as a physiological response to hyperinsulinaemia. The recent characterization of leptin receptors in pancreatic beta cells, liver and muscle suggests that leptin may influence insulin function and metabolism. Our study focuses on the possible relationship between leptin secretion and adipose tissue insulin-degrading capacity. DESIGN AND PATIENTS: Insulin and leptin were measured in arterial blood and in the epiploic vein of morbidly obese (n = 7) and non-obese patients (n = 7) who were undergoing abdominal surgery. Arteriovenous insulin difference (AV insulin) was considered an in vivo marker of insulin degradation by the omental fat tissue. Statistical comparison between venous and arterial leptin was used to assess endogenous leptin production. MEASUREMENTS: Insulin was measured using an oligoclonal IRMA and leptin levels were determined by using a specific radioimmunoassay. RESULTS: Morbidly obese patients were hyperinsulinaemic compared to non-obese patients according to arterial insulin levels (P = 0.049) but not to venous levels. Insulin cleavage capacity, nil in the control group, was clearly significant in the morbidly obese patients (P = 0.001). In the morbidly obese group, leptin levels in venous epiploic samples were significantly higher (P = 0.028) than in the arterial samples, confirming in situ the synthesis of leptin by human white adipose tissue. We also observed a correlation between insulin arterial levels and venous leptin concentrations (P = 0.009) which supports the chronic leptinogenic effect of insulin suggested in previous works. Finally, our results show that venous leptin levels are correlated with the extent of insulin cleavage by omental tissue (P = 0.033). CONCLUSIONS: Morbidly obese patients have a higher white adipose tissue insulin cleavage capacity, which could partially diminish hyperinsulinaemia-derived adverse effects. High leptin production, a consequence of high insulin levels, may act as a signal to the insulin-degrading tissues in order to lower insulinaemia.

Prognostic factors in meningococcal disease. Development of a bedside predictive model and scoring system. Barcelona Meningococcal Disease Surveillance Group.

CONTEXT: Meningococcal disease is associated with significant morbidity and mortality. Development of a prognostic model based on clinical findings may be useful for identification and management of patients with meningococcal infection. OBJECTIVES: To construct and validate a bedside model and scoring system for prognosis in meningococcal disease. DESIGN: Prospective, population-based study. SETTING: Twenty-four hospitals in the metropolitan area of Barcelona, Spain. PATIENTS: A total of 907 patients with microbiologically proven meningococcal disease. Patients diagnosed with meningococcal disease from 1987 through 1990 were used to develop the prognostic model, and those diagnosed in 1991 and 1992 were used to validate it. OUTCOME MEASURES: Clinical independent prognostic factors for mortality in meningococcal disease. The association between outcome and independent prognostic factors was determined by logistic regression analysis. A scoring system was constructed and tested using receiver operating characteristic curves. RESULTS: Among 624 patients in the derivation set, 287 (46%) were male, the mean age was 12.4 years, and 34 patients (5.4%) died. Among 283 patients in the validation set, 124 (43.8%) were male, the mean age was 12.7 years, and 17 patients (6.0%) died. In multivariate analysis, independent predictors of death were hemorrhagic diathesis (odds ratio [OR], 101; 95% confidence interval [CI], 30-333), focal neurologic signs (OR, 25; 95% CI, 7-83), and age 60 years or older (OR, 10; 95% CI, 3-34), whereas receipt of adequate antibiotic therapy prior to admission was associated with reduced likelihood of death (OR, 0.09; 95% CI, 0.02-0.4). Hemorrhagic diathesis was scored with 2 points, presence of focal neurologic signs with 1 point, age of 60 years or older with 1 point, and preadmission antibiotic therapy was scored as -1. The clinical scores of -1, 0, 1, 2, and 3 or more points were associated with a probability of death of 0%, 2.3%, 27.3%, 73.3%, and 100%, respectively. CONCLUSIONS: Hemorrhagic diathesis, focal neurologic signs, and age of 60 years or older were independent predictors of death in meningococcal disease, whereas receipt of adequate antibiotic therapy was associated with a more favorable prognosis. The scoring system presented is simple, is based on findings readily available at the bedside, and may be useful to help guide aggressive therapy.