Dipeptidyl peptidase 4 (DPP4) regulates various physiological pathways and has a pivotal role in glucose homeostasis. The objective of this study was to verify the association of a haplotype constituted by two single nucleotide polymorphisms (rs2268894 and rs6741949) in the DPP4 gene with type 2 diabetes mellitus (T2DM) and fasting glycemia-related variables in a sample of Brazilian older adults, taking serum levels and enzymatic activity of DPP4 into account. Clinical, biochemical, and anthropometric characteristics as well as DPP4 serum levels and enzymatic activity were determined in 800 elderly (≥60 years old) individuals. Assessment of polymorphic sites was performed by real-time PCR whereas haplotypes were inferred from genotypic frequencies. Statistical analyses compared measures and proportions according to T2DM diagnosis and DPP4 haplotypic groups. The most common haplotype consisted of the T-rs2268894/G-rs6741949 string, which was 20% more frequent among non-diabetics. Considering non-diabetic patients alone, carriers of the T/G haplotype had significantly lower levels of blood glucose, insulin, HOMA-IR index, and DPP4 activity. Among diabetic patients, the T/G haplotype was associated with lower DPP4 levels whereas glycemic scores were not affected by allelic variants. Our results suggested that the genetic architecture of DPP4 affects the glycemic profile and DPP4 serum levels and activity among elderly individuals according to the presence or absence of T2DM, with a possible implication of the T/G haplotype to the risk of T2DM onset.

The apolipoprotein B (APOB) gene contains several polymorphic sites described as risk modifiers for cardiovascular events. The objective of this study was to verify the association of the classic APOB Xba I polymorphism (rs693) with atherosclerotic risk factors in a segment of the Brazilian elderly population considering their usual dietary intake. Clinical and biochemical characteristics as well as total caloric and fat intake data were determined from 644 elderly individuals. Polymorphism analysis was performed by conventional polymerase chain reaction followed by enzyme restriction. Statistical analyses compared measures and proportions according to different APOB genotypic combinations. Statistically significant association was found between Xba I polymorphism and serum LDL, total cholesterol, and total lipid levels, with important elevations among T homozygotes compared to the other genotypes. There was homogeneity in all other parameters analyzed (including intake pattern), with a tendency for reduced levels of circulating apolipoprotein B among TT individuals. Our results pointed out that genetic variation in APOB affected the lipemic profile of elderly individuals in a context not biased by diet, generating a pattern suggestive of secretory disorder of lipoprotein particles, with possible implication in atherosclerotic risk.

Abstract Objective: To analyze the impact of I/D polymorphism of the angiotensin-converting enzyme gene on the responses of 24 h blood pressure, heart rate variability and nitric oxide after moderate aerobic exercise session. Method: Twenty seven hypertensive elderly were genotyped for the I/D polymorphism of the angiotensin-converting enzyme gene (D/D: n = 9; I/D: n = 9; I/I: n = 9) and performed a bout of aerobic exercise at 90% of anaerobic threshold. Measurements of mean blood pressure, heart rate variability and nitric oxide were performed before and during 24 h post-aerobic exercise session. Results: The D/D genotype showed impaired mean arterial pressure responses (elevation) in the nocturnal sleep (10:30 pm to 06:30 am) post-aerobic exercise when compared to rest (D/D = −4.2 ± 8.1 mmHg; p > 0.05, I/D = −9.2 ± 9.1 mmHg; p < 0.05 and I/I = −7.0 ± 6.9 mmHg; p < 0.05). Besides, in day time of 06:30 am to 10:30 am (next day) higher values of mean arterial pressure responses occur between D/D = 4.7 ± 4.6 mmHg vs. I/D = −2.0 ± 13.0 mmHg; p < 0.05. The carriers of the D allele, in addition to not release nitric oxide significantly post-aerobic exercise session (p > 0.05), showed reduced elevation of nitric oxide between genotypes immediately after aerobic exercise (D/D = 12.8 ± 135.3 μM and I/D = −8.7 ± 69.0 μM vs. I/I = 132.9 ± 188.7 μM; p < 0.05). Reduced elevation of heart rate variability post-aerobic exercise session occurred when compared to rest (D/D = 1 h: −0.08 ± 0.09 s; p < 0.05 and 24 h: −0.08 ± 0.11 s; p < 0.05). Conclusion: Elderly hypertensive individuals carrying the D/D genotype of the angiotensin converting enzyme gene showed impaired responses of blood pressure post-aerobic exercise, especially during sleep, and reduced heart rate variability during the 24 h post-aerobic exercise. Besides, to angiotensin converting enzyme genotypes with the presence of D allele (D/D and I/D) was impaired release of nitric oxide post-aerobic exercise session.

Resumo Objetivo: Analisar o impacto do polimorfismo I/D do gene da enzima conversora da angiotensina na pressão sanguínea, variabilidade da frequência cardíaca e óxido nítrico durante 24 h, em resposta a uma bateria moderada de exercícios aeróbicos. Método: Vinte e sete idosas hipertensas foram genotipadas para o polimorfismo I/D do gene da enzima conversora da angiotensina (D/D: n = 9; I/D: n = 9; I/I: n = 9) e realizaram uma sessão de exercício aeróbio à 90% do limiar anaeróbio. Medidas de pressão arterial média, variabilidade da frequência cardíaca e óxido nítrico foram coletadas antes e durante as 24 h seguintes, após a sessão de exercício aeróbio. Resultados: O genótipo D/D mostrou uma resposta inadequada da pressão arterial média (elevação) durante o sono após o exercício (22:30-06:30) em comparação ao repouso (D/D = -4.2 ± 8.1 mmHg; p > 0.05, I/D = -9.2 ± 9.1 mmHg; p < 0.05 e I/I = -7.0 ± 6.9 mmHg; p < 0.05). Além disso, durante o dia, de 06:30-10:30 da manhã (do dia seguinte), maiores valores de pressão arterial média ocorreram entre D/D = 4.7 ± 4.6 mmHg vs. I/D = -2.0 ± 13.0 mmHg; p < 0.05. O grupo carreador do alelo D, além de não revelar significância no óxido nítrico após a sessão de exercício, mostrou uma redução da elevação do óxido nítrico entre os genótipos logo após o exercício aeróbio (D/D = 12.8 ± 135.3 μM e I/D = -8.7 ± 69.0 μM vs. I/I = 132.9 ± 188.7 μM; p < 0.05). Ocorreu uma redução do R-Ri após os exercícios quando comparada com os valores do repouso (D/D = 1 h: -0.08 ± 0.09 s; p < 0.05 e 24 h: -0.08 ± 0.11 s; p < 0.05). Conclusão: Indivíduos idosos e hipertensos carreadores do genótipo D/D para o gene da enzima conversora da angiotensina mostraram resposta inadequada de pressão arterial pós-exercício aeróbio, especialmente durante o sono, e reduzida variabilidade da frequência cardíaca durante as 24 h seguintes pós-exercício. Além disso, o genótipo da enzima conversora da angiotensina com a presença do alelo D (D/D e I/D) teve sua liberação de óxido nítrico prejudicada nos momentos após a sessão de exercício aeróbio.

Resumen Objetivo: Analizar el impacto del polimorfismo I/D del gen de la enzima conversora de la angiotensina en la presión sanguínea, variación de la frecuencia cardíaca y óxido nítrico durante 24 h en respuesta a una batería moderada de ejercicios aeróbicos. Método: Veintisiete ancianas hipertensas fueron genotipadas para el polimorfismo I/D del gen de la enzima conversora de la angiotensina (D/D: n = 9; I/D: n = 9; I/I: n = 9) y realizaron una batería de ejercicios aeróbicos al 90% del umbral anaeróbico. Se realizaron medidas de la presión arterial media, variabilidad de la frecuencia cardíaca y óxido nítrico, antes y durante las 24 h siguientes después de una sesión de ejercicios aeróbicos. Resultados: El genotipo D/D presentó una respuesta inadecuada de la presión arterial media (aumento) durante el sueño nocturno después del ejercicio (22:30-06:30) en comparación con el reposo (D/D = -4.2 ± 8.1 mmHg; p > 0.05, I/D = -9.2 ± 9.1 mmHg; p < 0.05 and I/I = -7.0 ± 6.9 mmHg; p < 0.05). Por otro lado, durante el día, de 06:30 hasta las 10:30 de la mañana (del día siguinete) se registraron valores elevados del aumento de la presión arterial media en el genotipo D/D = 4.7 ± 4.6 mmHg vs. I/D = -2.0 ± 13.0 mmHg; p < 0.05. Las portadoras del alelo D, más allá de no mostrar significación en los niveles de óxido nítrico después de la sesión de ejercicio, mostraron una reducción del incremento de óxido nítrico entre los genotipos después del ejercicio aeróbico (D/D = 12.8 ± 135.3 μM y I/D = -8.7 ± 69.0 μM vs. I/I = 132.9 ± 188.7 μM; p < 0.05). Se observó una reducción del aumento de la variabilidad de la frecuencia cardíaca después de los ejercicios, cuando se compara con los valores de reposo (D/D = 1 h: -0.08 ± 0.09 s; p < 0.05 y 24 h: -0.08 ± 0.11 s; p < 0.05). Conclusión: Individuos ancianos e hipertensos portadores del genotipo D/D del gen de la enzima conversora de la angiotensina mostraron una respuesta inadecuada de la presión sanguínea postejercicio aeróbico, especialmente durante el sueño, y reducción de la variabilidad de la frecuencia cardíaca durante las 24 h siguientes tras el ejercicio. Además, el genotipo de la enzima conversora de la angiotensina, con presencia del alelo D (D/D e I/D), tiene la liberación de óxido nítrico alterada, después de la sesión de ejercicio aeróbico.

We investigated the effect of -174 G/C single-nucleotide polymorphism in the promoter region of the IL6 gene on plasma IL-6 levels and muscle strength, and the relationship between IL-6 levels and muscle strength in elderly women. The sample consisted of 199 elderly residents (73.0 ± 7.8 years old) from rest homes and the community in Belo Horizonte, MG, Brazil. -174 G/C polymorphism was determined by direct sequencing of the product by PCR, and plasma IL-6 concentrations were measured by ELISA. Muscle strength in the knee joint was evaluated using a Biodex System 3 Pro® isokinetic dynamometer. ANCOVA was used to determine the effect of polymorphism on IL-6 levels and muscle strength, and the Pearson correlation coefficient to assess the relationship between IL-6 levels and muscle strength. -174 G/C polymorphism was associated with the plasma IL-6 levels of elderly women (P < 0.01) since homozygotes for the G allele showed high IL-6 levels (GG 3.85 pg/mL, GC + CC 2.13 pg/mL). There was no association of polymorphism on muscle strength (P > 0.05). No association was found between IL-6 levels and knee extensor muscle (r = 0.087, P = 0.306) or flexor (r = -0.011, P = 0.894) strength. An interaction between -174 G/C polymorphism and housing conditions of the sample of elderly women was identified, with the effect of genotype on IL-6 levels being higher in the institutionalized elderly. These results support the evidence that -174 G/C polymorphism of the IL6 gene associates with individual variability of plasma IL-6 levels in elderly women.

The objective of the present study was to compare the effect of acute exercise performed at different intensities in relation to the anaerobic threshold (AT) on abilities requiring control of executive functions or alertness in physically active elderly females. Forty-eight physically active elderly females (63.8 ± 4.6 years old) were assigned to one of four groups by drawing lots: control group without exercise or trial groups with exercise performed at 60, 90, or 110% of AT (watts) and submitted to 5 cognitive tests before and after exercise. Following cognitive pretesting, an incremental cycle ergometer test was conducted to determine AT using a fixed blood lactate concentration of 3.5 mmol/L as cutoff. Acute exercise executed at 90% of AT resulted in significant (P < 0.05, ANOVA) improvement in the performance of executive functions when compared to control in 3 of 5 tests (verbal fluency, Tower of Hanoi test (number of movements), and Trail Making test B). Exercising at 60% of AT did not improve results of any tests for executive functions, whereas exercise executed at 110% of AT only improved the performance in one of these tests (verbal fluency) compared to control. Women from all trial groups exhibited a remarkable reduction in the Simple Response Time (alertness) test (P = 0.001). Thus, physical exercise performed close to AT is more effective to improve cognitive processing of older women even if conducted acutely, and using a customized exercise prescription based on the anaerobic threshold should optimize the beneficial effects.

In worldwide studies, interleukin-6 (IL-6) is implicated in age-related disturbances. The aim of the present report was to determine the possible association of IL-6 -174 C/G promoter polymorphism with the cytokine profile as well as with the presence of selected cardiovascular risk features. This was a cross-sectional study on Brazilian women aged 60 years or older. A sample of 193 subjects was investigated for impaired glucose regulation, diabetes, hypertension, and dyslipidemia. Genotyping was done by direct sequencing of PCR products. IL-6 and C-reactive protein were quantified by high-sensitivity assays. General linear regression models or the Student t-test were used to compare continuous variables among genotypes, followed by adjustments for confounding variables. The chi-square test was used to compare categorical variables. The genotypes were consistent with Hardy-Weinberg equilibrium proportions. In a recessive model, mean waist-to-hip ratio, serum glycated hemoglobin and serum glucose were markedly lower in C homozygotes (P = 0.001, 0.028, and 0.047, respectively). In a dominant hypothesis, G homozygotes displayed a trend towards higher levels of circulating IL-6 (P = 0.092). Non-parametric analysis revealed that impaired fasting glucose and hypertension were findings approximately 2-fold more frequent among G homozygous subjects (P = 0.042 and 0.043, respectively). Taken together, our results show that the IL-6 -174 G-allele is implicated in a greater cardiovascular risk. To our knowledge, this is the first investigation of IL-6 promoter variants and age-related disturbances in the Brazilian elderly population.