CONTEXT: Diabetes mellitus prevalence has been increasing worldwide due to factors like lifestyle changes and higher life expectancy. The Brazilian Multicenter Study performed between 1986 and 1988 evaluated the prevalence of diabetes and impaired glucose tolerance. OBJECTIVE:To assess the prevalence of diabetes and impaired glucose tolerance in the urban population aged 30-69 years of the city of Ribeirão Preto, SP, Brazil. TYPE OF STUDY:A two-stage, cross-sectional home survey. SETTING:Ribeirão Preto, São Paulo, Brazil. PARTICIPANTS:A random sample of 1,473 individuals. METHODS:The sample plan was drawn up using a sampling scheme of stage conglomerates according to sex, age and family head income. Subjects were first screened by fasting capillary glycemia (FCG). Those that screened positive (FCG 100 mg/dl) and every seventh consecutive person who screened negative (FCG < 100 mg/dl) was submitted to a 75 g oral glucose tolerance test. The diagnosis of diabetes and impaired glucose tolerance were based on World Health Organization criteria. RESULTS:The overall rates of diabetes and impaired glucose tolerance were 12.1 and 7.7%, respectively. Men and women had similar rates of diabetes (12.0 vs. 12.1%) and impaired glucose tolerance (7.9 vs. 7.3%). Differences in the rates for whites (11.6%) and nonwhites (13.3%) for diabetes were not significant, while impaired glucose tolerance was more prevalent among whites. The prevalences of diabetes and impaired glucose tolerance ranged from 3.3% and 2.6% in the 30-39 year age group to 21.7% and 11.3% in the 60-69 year age group, respectively. Obese subjects (BMI 30 kg/m 2 ) and those with a family history of diabetes (first-degree relatives) presented higher prevalences of diabetes (22.6% and 19.7%, respectively). CONCLUSIONS:The prevalence of diabetes in Ribeirão Preto was found to be comparable to that occurring in developed countries. With respect to the Brazilian Multicenter Study we verified an increased prevalence of diabetes but a similar prevalence of impaired glucose tolerance. These findings may reflect modifications in environmental factors and lifestyle that have been occurring in Brazilian cities like Ribeirão Preto, especially regarding increasing rates of sedentary living and obesity .

The metabolic derangement caused by diabetes mellitus may potentially affect bone mineral metabolism. In the present study we evaluated the effect of diabetes metabolic control on parathyroid hormone (PTH) secretion during stimulation with EDTA infusion. The study was conducted on 24 individuals, 8 of them normal subjects (group N: glycated hemoglobin -HbA 1C = 4.2 ± 0.2%; range = 3.5-5.0%), 8 patients with good and regular metabolic control (group G-R: HbA 1C = 7.3 ± 0.4%; range = 6.0-8.5%), and 8 patients with poor metabolic control (group P: HbA 1C = 12.5 ± 1.0%; range: 10.0-18.8%). Blood samples were collected at 10-min intervals throughout the study (a basal period of 30 min and a 2-h period of EDTA infusion, 30 mg/kg body weight) and used for the determination of ionized calcium, magnesium, glucose and intact PTH. Basal ionized calcium levels were slightly lower in group P (1.19 ± 0.01 mmol/l) than in group N (1.21 ± 0.01 mmol/l) and group G-R (1.22 ± 0.01 mmol/l). After EDTA infusion, the three groups presented a significant fall in calcium, but with no significant difference among them at any time. Basal magnesium levels and levels determined during EDTA infusion were significantly lower (P<0.01) in group P than in group N. The induction of hypocalcemia caused an elevation in PTH which was similar in groups N and G-R but significantly higher than in group P throughout the infusion period (+110 min, N = 11.9 ± 2.1 vs G-R = 13.7 ± 1.6 vs P = 7.5 ± 0.7 pmol/l; P<0.05 for P vs N and G-R). The present results show that PTH secretion is impaired in patients with poorly controlled diabetes.

Objective: Matrix metalloproteinase-9 (MMP-9) is involved in the atherosclerotic process and functional polymorphisms in the MMP-9 gene affect MMP-9 expression/activity, and are associated with cardiovascular diseases. However, no study has tested the hypothesis that functional MMP-9 polymorphisms could affect MMP-9 levels in obese children. We investigated whether three MMP-9 gene polymorphisms (C-1562T (rs3918242), 90(CA) (14À24) (rs2234681) and Q279R (rs17576)), or haplotypes, affect MMP-9 levels in obese children. Methods: We studied 175 healthy control children and 127 obese children. Plasma MMP-9, tissue inhibitor of MMPs (TIMP)-1 and adiponectin concentrations were measured using enzyme-linked immunosorbent assay. Results: We found similar MMP-9 genotypes, allelic and haplotypes distributions in the two study groups (P40.05). However, we found lower plasma MMP-9 concentrations in obese subjects carrying the CC or the QQ genotypes for the C-1562T and the Q279R polymorphisms, respectively, in obese children compared with children with the other genotypes, or with non-obese children with the same genotypes (all Po0.05). Moreover, we found lower MMP-9 levels and lower MMP-9/TIMP-1 ratios (which reflect net MMP-9 activity) in obese children carrying the H2 haplotype (which combines the C, H and Q alleles for the three polymorphisms, respectively) when compared with obese children carrying the other haplotypes, or with non-obese children carrying the same haplotype (Po0.05). Conclusions: Our findings show that MMP-9 genotypes and haplotypes affect MMP-9 levels in obese children and adolescents, and suggest that genetic factors may modify relevant pathogenetic mechanisms involved in the development of cardiovascular complications associated with obesity in childhood.

OBJECTIVE:To test the hypothesis that obese normotensive children and adolescents present impaired cardiac autonomic control compared to non-obese normotensive ones. METHODS:For this cross-sectional study, 66 children and adolescents were divided into the following groups: Obese (n=31, 12±3 years old) and Non-Obese (n=35, 13±3 years old). Obesity was defined as body mass index greater than the 95th percentile for age and gender. Blood pressure was measured by oscillometric method after 15 minutes of rest in supine position. The heart rate was continuously registered during ten minutes in the supine position with spontaneous breathing. The cardiac autonomic control was assessed by heart rate variability, which was calculated from the five-minute minor variance of the signal. The derivations were the index that indicates the proportion of the number of times in which normal adjacent R-R intervals present differences >50 miliseconds (pNN50), for the time domain, and, for the spectral analysis, low (LF) and high frequency (HF) bands, besides the low and high frequencies ratio (LF/HF). The results were expressed as mean±standard deviation and compared by Student's t-test or Mann-Whitney's U-test. RESULTS: Systolic blood pressure (116±14 versus 114±13mmHg, p=0.693) and diastolic blood pressure (59±8 versus 60±11mmHg, p=0.458) were similar between the Obese and Non-Obese groups. The pNN50 index (29±21 versus 43±23, p=0.015) and HF band (54±20 versus 64±14 normalized units - n.u., p=0.023) were lower in the Obese Group. The LF band (46±20 versus 36±14 n.u., p=0.023) and LF/HF ratio (1.3±1.6 versus 0.7±0.4, p=0.044) were higher in Obese Group. CONCLUSIONS: Obese normotensive children and adolescents present impairment of cardiac autonomic control.