Bioenergetic signatures of neurodevelopmental regression.

Background: Studies have linked autism spectrum disorder (ASD) to physiological abnormalities including mitochondrial dysfunction. Mitochondrial dysfunction may be linked to a subset of children with ASD who have neurodevelopmental regression (NDR). We have developed a cell model of ASD which demonstrates a unique mitochondrial profile with mitochondrial respiration higher than normal and sensitive to physiological stress. We have previously shown similar mitochondrial profiles in individuals with ASD and NDR. Methods: Twenty-six ASD individuals without a history of NDR (ASD-NoNDR) and 15 ASD individuals with a history of NDR (ASD-NDR) were recruited from 34 families. From these families, 30 mothers, 17 fathers and 5 typically developing (TD) siblings participated. Mitochondrial respiration was measured in peripheral blood mononuclear cells (PBMCs) with the Seahorse 96 XF Analyzer. PBMCs were exposed to various levels of physiological stress for 1 h prior to the assay using 2,3-dimethoxy-1,4-napthoquinone. Results: ASD-NDR children were found to have higher respiratory rates with mitochondria that were more sensitive to physiological stress as compared to ASD-NoNDR children, similar to our cellular model of NDR. Differences in mitochondrial respiration between ASD-NDR and TD siblings were similar to the differences between ASD-NDR and ASD-NoNDR children. Interesting, parents of children with ASD and NDR demonstrated patterns of mitochondrial respiration similar to their children such that parents of children with ASD and NDR demonstrated elevated respiratory rates with mitochondria that were more sensitive to physiological stress. In addition, sex differences were seen in ASD children and parents. Age effects in parents suggested that mitochondria of older parents were more sensitive to physiological stress. Conclusion: This study provides further evidence that children with ASD and NDR may have a unique type of mitochondrial physiology that may make them susceptible to physiological stressors. Identifying these children early in life before NDR occurs and providing treatment to protect mitochondrial physiology may protect children from experiencing NDR. The fact that parents also demonstrate mitochondrial respiration patterns similar to their children implies that this unique change in mitochondrial physiology may be a heritable factor (genetic or epigenetic), a result of shared environment, or both.

Aging effects on the encoding/retrieval flip in associative memory: fMRI evidence from incidental contingency learning.

Introduction: Associative memory is arguably the most basic memory function and therein constitutes the foundation of all episodic and semantic memory processes. At the same time, the decline of associative memory represents a core feature of age-related cognitive decline in both, healthy and pathological (i.e., dementia-related) aging. The neural mechanisms underlying age-related impairments in associative memory are still not fully understood, especially regarding incidental (i.e., non-intentional) learning. Methods: We investigated the impact of age on the incidental learning and memory retrieval of face-name combinations in a total sample of 46 young (N = 23; mean age = 23.39 years) and elderly (N = 22, mean age = 69.05 years) participants. More specifically, particular interest was placed in age-related changes in encoding/retrieval (E/R) flips, which denote a neural antagonism of opposed activation patterns in the same brain region during memory encoding and retrieval, which were assessed using fMRI. Results: According to our hypothesis, the results showed a significant age-related decline in the retrieval performance in the old group. Additionally, at the neural level, we discovered an abolished E/R flip in the right anterior insula and a joint but reduced E/R flip activation magnitude in the posterior middle cingulate cortex in older subjects. Discussion: In conclusion, the present findings suggest that the impaired neural modulation of the E/R flip in the right aIC might be a sensitive marker in the early detection of neural aging.

Perceived competence in ice hockey and its associations with relative age, early sport specialization, and players' position.

Introduction: Ice hockey is a sport that has gained much attention in recent times, particularly concerning the development of young players. In the domain of youth sport development, one significant factor that must be considered is the perceived competence of players. This variable is closely linked to positive psychological outcomes and sustained practice. However, there is a lack of understanding about how other important developmental factors such as age, early sport specialization, players' position and relative age affect players' perceived competence. Therefore, the objective of this study is to explore the relationships between these developmental factors, perceived ice hockey competence and a global measure of perceived sport competence. Methods: Data was drawn from 971 players (14.78 ± 1.61 mean age), who completed on-line questionnaires, from which we conducted path analyses involving all variables. Results: Younger players tend to display higher perceived competence scores than older players. Additionally, players who opted to specialize earlier also reported higher perceived competence. Furthermore, forwards and defensemen had differing perceptions of their competence, which was in line with their respective roles on the ice. The study also showed relative age effects, in which players who were born earlier relative to the selection period tend to perceive themselves more advantageously in three components of perceived competence. Discussion: Based on these findings, several recommendations are proposed for coaches and decision-makers to encourage the positive development of ice hockey players. The study highlights that ice hockey-specific competencies are influenced by various factors, such as early sport specialization, relative age effect, player age, and position.

Is There a Relationship Between Birth Quartile and Vertical Jump Performance Among Young Male Elite Volleyball Athletes?

Vertical jump is an important skill that influences volleyball performance. In this study, we analyzed the relationship between vertical jump performance and birth quartile of Brazilian male youth volleyball players. We calculated chi-square goodness-of-fit tests to compare the athletes' birthdate distributions in quarters of their birth years (Q1, Q2, Q3, and Q4) according to player age categories (U17, U18, U19, and U21). We calculated one-way ANOVAs to compare spike jump and block jump heights of players born in different quarters of the same year. Overall, we found a relative age effect (i.e., more players with birth dates early in the birth year) in U17 (p < .001), U18 (p < .001), U19 (p < .001), and U21 (p = .04). Regarding vertical jump performance, U18 athletes born in Q2 reached higher spike jump heights (p = .006) and block jump heights (p = .002) than athletes born in Q4, and U19 athletes born in Q1 reached higher block jump heights than athletes born in Q3 (p = .049). There were no significant differences in vertical jump performance across birth quartiles among U17 and U21 athletes. Thus, a relative age effect was present in all age categories but not always reflected in vertical jump performance. Volleyball coaches and policymakers are still advised to employ strategies to ensure fairer opportunities for players born later in the year of their eligibility dates, as we found RAE to be sometimes, but not always, related to higher spike or block jump heights even among these older adolescents and young adult athletes.

Immunological features of ESRD patients undergoing hemodialysis of various ages.

AIMS: To investigate the immunological characteristics of hemodialysis (HD) patients with end-stage renal disease (ESRD) of various ages, and the impact of age-related immune alterations on these patients, with a focus on peripheral T cells. METHODS: From September 2016 to September 2019, HD patients were enrolled and followed prospectively for 3 years. Patients were divided into three groups based on their ages: < 45, 45 to 64, and ≥ 65. The distribution of T cell subsets in different age groups was investigated and compared. The effects of altered T cell subsets on overall survival were also investigated. RESULTS: A total of 371 HD patients were enrolled. The reduced number of naive CD8+ T cells (P < 0.001) and increased number of EMRA CD8+ T cells (P = 0.024) were independently associated with the advanced age among all T cell subsets studied. Patient survival may be affected by numerical changes in naive CD8+ T cells. However, when HD patients were < 45 or ≥ 65 years, the reduction had no significant impact on survival. Only in HD patients aged 45 to 64 years, the number of naïve CD8+ T cells found to be insufficient but not deficient, identified as an independent predictor of poor survival. CONCLUSIONS: The most significant age-related immune change in HD patients was a decrease in peripheral naive CD8+ T cells, which was an independent predictor of 3-year overall survival in HD patients aged 45 ~ 64 years.

The impact of relative age effects on psychosocial development: A systematic review.

BACKGROUND: Within the same school class, it is usual to find children who differ in age by almost a full calendar year. Although associations between being relatively young and poor academic outcomes are well documented, and relatively consistent, the associations between being relatively young and psychosocial outcomes are less clearly documented. AIMS: To review research which presents data relating to associations between a child's relative age and their psychosocial development. METHODS: A systematic review was conducted and reported in accordance with PRISMA guidelines. RESULTS: Fifty-nine papers met the inclusion criteria. The outcomes of the narrative synthesis and three meta-analyses found consistent, but very small, associations with relative age indicating that those who are relatively young are more likely to have more negative behaviour, mental well-being, and social experiences. CONCLUSIONS: Although being relatively young is associated with more negative psychosocial outcomes, the magnitude of these associations is consistently small. Furthermore, many of the outcome measures used are likely to be the result of multiple influences, not limited to the effects of relative age. Therefore, the findings are reassuring as they suggest that relative age itself is unlikely to substantially increase an individual's risk of poor psychosocial development.

Assessment of tree-ring mercury radial translocation and age effect in Masson pine: Implications for historical atmospheric mercury reconstruction.

The tree ring has been regarded as an emerging archive to reconstruct historical atmospheric mercury (Hg) trends, but with the large knowledge gaps in the reliability. In this study, we comprehensively evaluated the Hg source, radial translocation and age effect of Masson pine (Pinus massoniana) tree ring at Mt. Jinyun in Chongqing, to assess the suitability of such tree ring as the archive of atmospheric Hg. Results showed that distinct variabilities among Masson pine tree-ring Hg concentration profiles. The Hg concentration significantly increased along with stem height (P < 0.05), indicating the Hg in tree rings mainly derived from foliage uptake atmospheric Hg. We found a distinct age effect that the tree ring of young trees had the higher Hg concentration. Besides, we used the advection-diffusion model to demonstrate how Hg concentration shifted by the advection or/and diffusion in tree rings. The modeling results showed that the advection induced radial translocation during the young growth period of tree was a plausible mechanism to result in the tree-ring Hg record largely different from the trend of anthropogenic Hg emissions in Chongqing. We finally suggest that in further Hg dendrochemistry, better discarding the tree-ring Hg profile of the young growth period to reduce impacts of the radial translocation and age effect.

Effects of paternal and chronological age on BEGAIN methylation and its possible role in autism.

Children from old fathers carry an increased risk for autism spectrum (ASD) and other neurodevelopmental disorders, which may at least partially be mediated by paternal age effects on the sperm epigenome. The brain enriched guanylate kinase associated (BEGAIN) protein is involved in protein-protein interactions at and transmission across synapses. Since several epigenome-wide methylation screens reported a paternal age effect on sperm BEGAIN methylation, here we confirmed a significant negative correlation between BEGAIN promoter methylation and paternal age, using more sensitive bisulfite pyrosequencing and a larger number of sperm samples. Paternal age-associated BEGAIN hypomethylation was also observed in fetal cord blood (FCB) of male but not of female offspring. There was no comparable maternal age effect on FCB methylation. In addition, we found a significant negative correlation between BEGAIN methylation and chronological age (ranging from 1 to 70 years) in peripheral blood samples of male but not of female donors. BEGAIN hypomethylation was more pronounced in male children, adolescents and adults suffering from ASD compared to controls. Both genetic variation (CC genotype of SNP rs7141087) and epigenetic factors may contribute to BEGAIN promoter hypomethylation. The age- and sex-specific BEGAIN methylation trajectories in the male germ line and somatic tissues, in particular the brain, support a role of this gene in ASD development.

Different hydraulic and photosynthetic responses to summer drought between newly sprouted and established Moso bamboo culms.

The subtropical regions in China are prone to recurrent summer droughts induced by the Western Pacific Subtropical High-Pressure, which has induced the death of tens of millions of culms of Moso bamboo (Phyllostachys edulis (Carriere) J. Houzeau), a widely distributed giant bamboo with high economic and ecological values. In the future, the intensity and frequency of the summer drought are projected to increase in these areas due to global climate change, which may lead to significant age-specific mortality of Moso bamboo. So far, it is still unclear about the age-specific response mechanisms of hydraulic traits and carbon balance of Moso bamboo when it is suffering to an ongoing summer drought. This study aimed to investigate the hydraulic and photosynthetic responses of newly sprouted (1 year old) and established (2-5 years old) culms of Moso bamboo to summer drought, which was manipulated by throughfall reduction in Lin'an of Zhejiang. The results showed that both newly sprouted and established culms had a gradually weakening hydraulic conductivity and photosynthesis during the whole drought process. In the early stage of the manipulated drought, the established culms had more loss of hydraulic conductivity than the newly sprouted culms. However, the newly sprouted culms had significant more loss of hydraulic conductivity and lower photosynthetic rates and stomatal conductance in the middle and late stages of the manipulated drought. The results suggest that the newly sprouted culms were more susceptible to summer drought than established culms due to the combined effects of hydraulic damage and photosynthetic restriction, explaining why the newly sprouted culms have higher mortality than elder culms when subjected to extreme drought. These findings provided insights into the mechanisms of Moso bamboo's age-specific drought-induced mortality, which will help for the anti-drought management of bamboo.

Are Late-Born Young Soccer Players Less Mature Than Their Early-Born Peers, Although No Differences in Physical and Technical Performance Are Evident?

The aim of the study was to compare the status of somatic maturity, anthropometry, strength, speed, and soccer-specific technical skills of players from leading youth soccer academies born in different quarters of the same calendar year. A total of 678 young male soccer players from eight leading Russian soccer academies took part in the study. The following anthropometric measures and physical characteristics were measured: height, weight, body mass index, countermovement jumps (CMJ), 5, 10, and 20 m sprints, speed dribbling, foot and body ball juggling, and short and long pass accuracy. The determination of somatic maturity as a percentage of projected adult height was collected. All subject dates of birth were divided into four quartiles according to the month of birth. The analysis of all data obtained was conducted both within the total sample and by quartiles of birth, according to the age group categories of 12-13 years, 14-15 years, and 16-17 years and the degree of somatic maturity. There was a widespread relative age effect, with 43.5% of early-born players and only 9.6% of late-born players representing the sample. Early-born players were more mature than late-born players (p < 0.001 and p < 0.001) but had no statistically significant differences in strength, speed, or soccer-specific skills.

Neural specialization to English words in Chinese children: Joint contribution of age and English reading abilities.

N1 tuning to words, a neural marker of visual word recognition, develops by an interaction between age and ability. The development of N1 tuning to a second learnt print is unclear. The present study examined the joint contribution of age and English reading abilities to N1 amplitude and tuning to English print in Chinese children in Hong Kong. EEG signals were recorded from 179 children (six to nine years old) while they were performing a repetition detection task comprised of different print stimuli measuring three types of tuning, i.e., coarse tuning (real word versus false font), fine tuning (real versus nonword), and lexicality effect (real versus pseudo word). Children were assessed in English word reading accuracy (EWR) and English sub-lexical orthographic knowledge (EOK). Results indicated that coarse tuning decreased with age but increased with EWR and EOK. Fine tuning uniquely increased with EOK, and the lexicality effect increased with EWR. At last, higher EWR was linked to less right-lateralized coarse tuning in younger children. Taken together, the findings support the visual perceptual expertise account in the L2 context, in that N1 coarse tuning, fine tuning, and lexicality effect are driven by skill improvement.

Effect of an Early-Age Exposure on the Degradation Mechanisms of Cement Paste under External Sulfate Attack.

Among the most significant causes of concrete degradation is ESA (external sulfate attack). The majority of studies are currently conducted on samples that have been saturated and matured. Concrete structures, however, are exposed to the environment once the formwork has been removed. The purpose of this study is to determine what effects early exposure to external sulfates may have on degradation mechanisms. Microstructure, physical, and chemical behavior are monitored using a variety of experimental techniques, including NMR (27Al and 29Si), ICP, XRD, MIP, and SEM. Based on expansion measurements, mature Portland cement paste, unlike the early-age case, degraded rapidly due to the presence of compressed ettringite and gypsum, highlighted by SEM analysis. During ESA, sulfate ions diffuse through the cement matrix and are bound by chemical agents. Chemical analyses indicate that the chemical mechanism varies with the duration of curing. At an early age, external sulfates and aluminates are the most important reagents. For matured cases, these reagents include external sulfates, calcium derived from CH dissolution, and aluminates derived from the total dissolution of AFm.

The Consequentialist Scale: Translation and empirical investigation in a Greek sample.

The Consequentialist Scale (Robinson, 2012) [89] assesses the endorsement of consequentialist and deontological moral beliefs. This study empirically investigated the application of the Greek translation of the Consequentialist Scale in a sample of native Greek speakers. Specifically, 415 native Greek speakers completed the questionnaire. To uncover the underlying structure of the 10 items in the Consequentialist Scale, an Exploratory Factor Analysis (EFA) was conducted. The results revealed a three-factor solution, where the deontology factor exhibited the same structure as the original work by Robinson (2012) [89], while the original consequentialism factor split into two separate factors. Significant Pearson's r correlations were observed between age and responses to the Consequentialist Scale. Separate EFAs were conducted for two age groups based on a medial split: younger (36 years old or less) and older (more than 36 years old). Interestingly, the younger group exhibited a two-factor solution with the same structure as the original work, while the older group showed a three-factor solution. A hierarchical k-means cluster analysis revealed that the cluster of participants who scored higher in deontology compared to consequentialism primarily consisted of older participants, whereas the two other clusters comprised of younger participants exhibited the reverse pattern. Neither gender nor previous experience with philosophy significantly affected scores on the Consequentialist Scale. Overall, our study provides evidence that the Consequentialist Scale is suitable for use in the Greek population.

Heart rate variability in patients with psychiatric disorders from adolescence to adulthood.

OBJECTIVE: Age is associated with changes in autonomic nervous system activity. These changes are assessed using heart rate variability(HRV) indicators; however, the effect of age on HRV in patients with psychiatric disorders remains unclear. Our study aimed to explore this effect and determine its variance across different lifespans. METHOD: Consecutive patients(N = 3315), comprising 1833 patients with psychotic disorders, 1040 with mood disorders, and 442 with anxiety disorders, were recruited. The patients were divided into four age groups: adolescence(10-24 years), early adulthood(25-39 years), middle adulthood(40-59 years), and late adulthood(60+ years). HRV indicators were measured during a 5-min rest period. RESULTS: The heart rate and HRV indices were higher in the adolescent and early adulthood groups than they were in the middle and late adulthood groups(increased HRV is beneficial for health, while reduced HRV is detrimental). Age and all the HRV indices were negatively correlated(r-values 0.153-0.350, p < 0.001), with these correlation patterns being more evident in the adolescent and early adulthood groups than in the middle and late adulthood groups. Stratified by sex, the low-frequency/high-frequency ratio was higher in men than in women across most age groups(p < 0.05), except the late adulthood group(p = 0.085). Stratified by diagnosis, most HRV variables(except very low-frequency) were lower in the psychotic disorder group than they were in the mood and anxiety disorder groups, especially in middle and late adulthood patients. After adjusting for confounders, the HRV variables were significantly associated with age, while older age was associated with lower HRV. CONCLUSIONS: These results indicate that the substantial reduction in HRV with age in patients with psychiatric disorders. The association remains significant after correction for sex, heart rate, and diagnoses; this may prove useful to clinical practice and further research.

Analysis of age, period, and birth cohort effects on suicide mortality in Brazil and the five major geographic regions.

OBJECTIVE: Estimate the effects of age, period, and birth cohort on suicide mortality in Brazil by major geographic region in the overall population and by sex. METHODS: This was a time trend ecological study. National and regional suicide mortality data from 1981 to 2020 were analyzed for the overall population and by sex. Age, period, and cohort effects were calculated with a Poisson regression model using estimable functions with the Epi package of the R statistical program, version 4.2.1. RESULTS: There were 272,716 suicides in individuals ranging from 20 to 79 years old. In the overall population, the age model-adjusted suicide mortality rates showed an upward pattern for Brazil. The most recent cohort showed the highest associated risk, 1.67 (95%CI 1.63; 1.71), while for the reference period, it was the highest risk among all the periods. CONCLUSIONS: Suicide mortality rates have shown an upward trend with advancing age in both men and women in the Brazilian population. However, the behavior of the period effect and cohort depends on the population analyzed and regional distribution.

Relative Age Effects and Self-Organized Sport Practices Among Adults.

Purpose: Given that previous research on relative age effects (RAEs) has only focused on organized sport, the aim of this exploratory study was to examine whether this phenomenon also existed among self-organized practitioners. In relation to that, a second aim was to know whether self-organized sport practices could be favored by late-born practitioners as a result of a strategic adaptation. Method(s): Representative sub-samples of 474 soccer players, 363 basketball players, 2,536 swimmers, 1,788 strength training practitioners, 1,873 pétanque players, 973 table tennis players and 2,136 runners were analyzed. Results: The results did not show any significant RAEs, including in sport practices that are sensitive to this phenomenon such as soccer or basketball. The results did not show any significant overrepresentation of late-born people either. Conclusion: This study suggests that self-organized sport practices are not impacted by the RAEs. This finding is interesting because self-organized sport practice is the most important one in numbers.

Aging effect and test-retest reliability of the sinusoidal harmonic acceleration test and velocity step test using nanotorque rotatory chair.

Introduction: Rotatory chair testing has been used to evaluate horizontal canal function. Frequently used tests include sinusoidal harmonic acceleration test (SHAT) and velocity step test (VST). Objectives: Assessment of age effect on the SHAT and VST and assessment of test-retest reliability of the parameters of those two tests. Methods: A prospective study was performed on 100 subjects with no ear or vestibular complaints and normal vestibular evaluation. They were divided into two groups; Group A: below 50 years of age and Group B: 50 years of age or above. SHAT was presented at frequencies 0.02, 0.04, 0.08, 0.16, 0.32, 0.64 Hz with a peak velocity of 60°/s. VST was performed using a maximum velocity of 100°/s with acceleration and deceleration of 200°/s2. Thirty subjects were tested twice to assess reliability. Results: Study participants ranged in age from 20 to 67 years. Regarding group A, the mean age was 30.92 ± 7.31 and 55.36 ± 4.61 for group B. No significant differences were found in SHAT parameters between the two groups. As well, there was no significant difference in VST per-rotatory time constant, however, post-rotatory time constant was significantly longer for Group B (P value < 0.05). Intraclass correlation coefficient (ICC) values showed moderate to good reliability (ICC 0.580-0.818) for SHAT parameters for the lower frequencies and indicated moderate reliability for VST time constant (ICC 0.509-0.652). Conclusions: Age has no significant effect on the parameters of SHAT and VST. Test-retest reliability is generally good for both tests.

The birthplace and relative age effects in Brazilian olympic athletes: a cross-national comparison.

Purpose: Our purpose was to verify the existence of birthplace and relative age effect (RAE), as well as the association between birthplace effect and RAE among Brazilian athletes competing in the Olympic Games. Methods: Data included information about Brazilian Summer Olympic athletes from 1920 to 2021. To investigate RAE, athletes' birthdate was distributed into birth quartiles (Q1: Jan-Mar; Q2: Apr-Jun; Q3: Jul-Sep; Q4: Oct-Dec), while birthplace effect was assessed considering the state and the region (Southeast; Northeast; South; North; and Midwest) of birth. The Chi-square test (χ2) was used to verify differences between the birthplace effect and RAE. Results: The sample consisted of 388 Brazilian athletes of both sexes, distributed in 38 sports modalities from 23 Brazilian states (Southeast = 66.5%; South = 14.4%; Northeast = 12.1%; North = 1.5%; Midwest = 5.4%). For both sexes, most of the athletes were from the São Paulo state (37.4%), followed by Rio de Janeiro (18.3%), both from the Southeast region. For birthdate distribution according to birthplace, it was observed that the North region presented the highest frequency of athletes born in Q1 (50%), followed by the Northeast and Southeast regions. No significant differences were found for the birthplace effect (χ2 = 5.69, value of p = 0.128) and RAE between sexes (χ2 = 0.530, value of p = 0.912), nor was shown an association between the birthplace effect and RAE. Conclusion: Most Brazilian Olympic athletes are from the Southeast region, but no RAE was established regarding their birthplace. Results from the present study can guide sports public policies in Brazilian regions, especially in the Midwest, North, and Northeast regions, which are underrepresented in Brazilian high-performance sports.

Stomach cancer incidence trends in selected Latin America countries: Age, period, and birth-cohort effects.

BACKGROUND: to explore the age, period, and birth-cohort effects on stomach cancer incidence trends during 3 decades in selected Latin American countries. METHODS: a time-trend study was performed using Cancer Incidence in Five Continents data from high-quality population-based cancer registries(PBCRs) in Latin American countries. Crude and age-standardized incidence rates(ASRIs) were calculated. Time trends in ASRIs were assessed using the average annual percentage change(AAPC). Age-period-cohort effects were estimated by Poisson regression for individuals aged between 20 and 79 years with stomach cancer informed by PBCRs from 1983 to 2012 in Cali(Colombia); from 1982 to 2011 in Costa Rica; and from 1988 to 2012 for Goiania(Brazil) and Quito(Ecuador). The goodness-of-fit model was tested using the deviance of the models. RESULTS: a decrease in age-standardized incidence rates was observed for both genders in all populations covered by PBCRs, except for young men from Cali(AAPC 3.89 95 %IC: 1.32-7.29). The age effect was statistically significant in all areas, and the curve slope reached peaks in the older age groups. The cohort effect was observed in all PBCRs. Regarding the period effect, an increased ratio rate was observed for both genders in Costa Rica(1997-2001 women RR 1.11 95 %CI: 1.05-1.17; men RR 1.12 95 %CI: 1.08-1.17) and Goiânia(2003-2007 women RR 1.21 95 %CI: 1.08-1.35; men RR 1.09 95 %CI: 1.01-1.20), while Quito(1998-2002 women RR 0.89 95 %CI: 0.81-0.98; men RR 0.86 95 %CI: 0.79-0.93) presented a decrease. CONCLUSION: the present study showed a decreasing gastric cancer trend for over the past 30 years with gender and geographic variations. Such a decrease seems to be mainly a result of cohort effects, suggesting that the economic market opening process led to changes in the risk factor exposures over successive generations. These geographic and gender variations may reflect cultural/ethnic/gender differences and differences in dietary and smoking rate patterns. However, an increased incidence was observed for young men in Cali, and additional studies are needed to determine the cause of the increasing incidence in this group.