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PubMed2025

Peruvian Population Genomics: Unraveling the Genetic Landscape and Admixture Dynamics of Urban Populations.

Latin American populations exhibit high genetic and phenotypic diversity shaped by complex admixture histories, yet remain underrepresented in genomic research. Here, we analyze genome-wide data from 432 urban individuals across 13 regions of Peru, including 346 newly genotyped from the Peruvian Genome Project. We revealed fine-scale population structure and demographic patterns shaped by both ancient and recent events. Indigenous American ancestries in urban individuals trace back to ancient north-south interactions consisted with archaeological records, while admixture events occurring within the last 8-10 generations involved sources already admixed between distinct ancestral lineages. Identity-by-descent analyses reveal sustained gene flow in southern Peru, while effective population size trends highlight demographic stability in Lima over the past 25 generations. Sex-biased admixture patterns suggest Indigenous ancestry contribution preferentially mediated by females. These findings offer a comprehensive view of Peru's genetic heritage, advancing our understanding of human genetic diversity and historical demographic processes in Latin America.

Admixture↗

PubMed2002

A generalized discriminant rule when training population and test population differ on their descriptive parameters.

Standard discriminant analysis methods make the assumption that both the labeled sample used to estimate the discriminant rule and the nonlabeled sample on which this rule is applied arise from the same population. In this work, we consider the case where the two populations are slightly different. In the multinormal context, we establish that both populations are linked through linear mapping. Estimation of the nonlabeled sample discriminant rule is then obtained by estimating parameters of this linear relationship. Several models describing this relationship are proposed and associated estimated parameters are given. An experimental illustration is also provided in which sex of birds that differ morphometrically over their geographical range is to be deterrmined and a comparison with the standard allocation rule is performed. Extension to a partially labeled sample is also discussed.

Animals↗

PubMed1978

Distribution of HLA antigens in a Mexican--American population and a comparison with two similar populations from different geographical locales.

The frequencies of 32 HLA antigens of the A and B series were determined in a previously unstudied population of Mexican-Americans in South Texas. The phenotype and gene frequencies for this group are presented and are contrasted with those determined in studies of Mexican/Mexican--American populations from two different locales. The statistically significant differences observed emphasize the need for indigenous controls when evaluating racially heterogeneous populations for disease-associated HLA antigens.

California↗

PubMed1989

Effect of maternal age distribution and prenatal diagnosis on the population rates of Down syndrome--a comparative study of nineteen populations.

We analyzed published data from 1980-85 on maternal age specific rates of Down syndrome in nineteen malformation monitoring systems. In the comparisons, we used maternal age specific Down syndrome baseline rates collected in Sweden using multiple sources and from a period before intense prenatal diagnosis. We supposed that no real maternal age specific risk difference exists between different populations, and that ascertainment of cases is independent of maternal age. With these suppositions, most programs had an ascertainment level of 70-90%, and some had about the same but none had a higher ascertainment level than that in the Swedish baseline. Marked differences in maternal age distribution in the populations studied resulted in a 12.3% standard deviation of the average population Down syndrome rate. The highest theoretical rate (estimated from actual maternal age distribution and Swedish baselines) was found in Spain (20% above average), the lowest in Czechoslovakia (24% below average). The estimated average effect of prenatal diagnosis was a decrease of only 6%, but in Denmark it was 25% and in Sweden and France:Paris 13%.

Adult↗

PubMed2001

The Stockholm populations of Adalia bipunctata (L) (Coleoptera: Coccinellidae)--a case of extreme female-biased population sex ratio.

The genetic composition and sex ratio in the Stockholm populations of Adalia bipunctata have been studied. The overall frequency of melanics is 3.2%, which is significantly lower than in the populations of St. Petersburg and other large cities along the Baltic Sea. The secondary sex ratio in the Stockholm populations is female-biased 82:18. More than half of A. bipunctata females are infected with the male-killing Spiroplasma bacterium. Beetles of the co-existing species Adalia decempunctata are infected with a different bacterium belonging to the genus Rickettsia.

Animals↗

PubMed1978

Immunoglobulin allotypes in African populations. I. Gm--Am haplotypes in a Nigerian population.

The study of immunoglobulin allotypes in various Negro populations has shown that their polymorphism is different from that in other populations. This particularly true for the alleles of the gamma3 and alpha2 locus. Numerous investigations have been made in which a limited number of markers were determined. It seems to be of importance to compare the results of the determination of all markers known at present in different tribes from various African countries. Such information may ultimately lead to additional support for theories on the origin and migration of early African inhabitants. In this paper we resent the results of the study of the first of a series of studies on African populations.

Black People↗

PubMed1998

A survey of oral health in a population of adults with developmental disabilities: comparison with a national oral health survey of the general population.

During 1991, an oral health assessment of 101 adults with developmental disabilities aged from 21 to 53 years was undertaken as part of a broader health survey which also included medical, psychological and nutritional assessments. The study group consisted of a random sample of adults chosen from the developmentally disabled population known to be living in the lower North Shore area of Sydney. This paper describes the results of the oral health assessment and compares them with an oral health survey of the Australian population done in 1987/88. Forty-six per cent of the study group were males (mean age 33.5 years) and 54 per cent were females (mean age 33.0 years). Compared with similar age subgroups in the Australian population, the following factors were more frequently reported in the developmentally disabled group: a dental visit in the last 12 months (65 per cent vs 50 per cent; Odds Ratio (OR) 1.9:95 per cent Confidence Interval (CI): 1.3-2.8); use of public rather than private dental services (42 per cent vs 6 per cent; OR 11.3:95% CI 7.5-16.9); oral mucosal pathology requiring treatment (15 per cent vs 2 per cent; OR 8.5:95% CI 5.2-13.8); severe periodontal disease (16 per cent vs 3 per cent; OR 6.9:95% CI 4.2-11.4); and moderate to severe malocclusion (26 per cent vs 11 per cent; OR 2.1:95% CI 1.3-3.5). Fifty-eight per cent of subjects felt they needed no dental treatment but on examination of the oral mucosa, periodontal tissues and teeth, over 90 per cent were found to require some sort of dental treatment.

Adult↗

PubMed1997

Epidemiological relatedness and clonal types of natural populations of Escherichia coli strains producing Shiga toxins in separate populations of cattle and sheep.

Two separate animal populations consisting of a herd of cattle (19 animals) and a flock of sheep (25 animals) were investigated for strains of Escherichia coli producing Shiga toxins (STEC) over a time period of 6 months. Thirty-three STEC were isolated from 63.2% of cattle and grouped into 11 serotypes and eight electrophoretic types (ETs) by multilocus enzyme analysis. In sheep, 88% of the animals excreted STEC (n = 67 isolates) belonging to 17 different serotypes and 12 different ETs. STEC from cattle and sheep differed with respect to serotype, and only 4 of the 16 ETs occurred in both animal populations. In cattle, ET14 (O116:H21) strains predominated, whereas other STEC serotypes occurred only sporadically. The predominating STEC types in sheep were ET4 (O125 strains), ET11 (O128:H2 and others), and ET14 (O146:H21). In contrast to their diversity, STEC originating from the same animal population were similar with respect to Shiga toxin (stxy genes. Almost all STEC isolated from cattle were positive for stx2 and stx2c; only one was positive for stx1. In sheep, almost all STEC isolated were positive for stx1 and stx2, whereas stx2c was not found. XbaI-digested DNAs of genetically closely related O146:H21 strains have different restriction profiles which were associated with size alterations in XbaI fragments hybridizing with stx1- and stx2-specific DNA probes. Our results indicate that stx-encoding bacteriophages might be the origin of the genetic heterogeneity in STEC from animals.

Animals↗

PubMed2001

Excess mortality in a population with diabetes and the impact of material deprivation: longitudinal, population based study.

OBJECTIVES: To establish the age and sex specific mortality for people with diabetes in comparison with local and national background populations; to investigate the relationship between mortality and material deprivation in an unselected population with diabetes. DESIGN: Longitudinal study, using a population based district diabetes register. SETTING: South Tees, United Kingdom. PARTICIPANTS: All people known to have diabetes living in Middlesbrough and Redcar and Cleveland local authorities on 1 January 1994. MAIN OUTCOME MEASURE: Death, from any cause, between 1 January 1994 and 31 December 1999. RESULTS: Over the six years of the study 1205 (24.9%) of 4842 participants died. All cause standardised mortality ratios for type 1 diabetes were 641 (95% confidence interval 406 to 962) in women and 294 (200 to 418) in men, and those for type 2 diabetes were 160 (147 to 174) in women and 141 (130 to 152) in men. Cause specific standardised mortality ratios were increased for ischaemic heart disease, cerebrovascular disease, and renal disease; no reductions in mortality from other causes were seen. The risk of premature death increased significantly with increasing material deprivation (P<0.001). CONCLUSIONS: Diabetes is associated with excess mortality, even in an area with high background death rates from cardiovascular disease. This excess mortality is evident in all age groups, most pronounced in young people with type 1 diabetes, and exacerbated by material deprivation. Aggressive approaches to the management of cardiovascular risk factors could reduce the excess mortality in people with diabetes.

Adolescent↗

PubMed2025

Health conditions in adults with atrial fibrillation compared with the general population: a population-based cross-sectional analysis.

BACKGROUND: Atrial fibrillation (AF) prevalence is rising due to population ageing and comorbidity is an increasing problem. The aim of this study was to examine the prevalence and association of coexisting health conditions among adults with AF in the general population. METHODS: Cross-sectional analysis of Clinical Practice Research Datalink (CPRD) primary care electronic medical records in England linked to hospital admissions as of 30 November 2015. CPRD is broadly representative of the UK general population in terms of age, sex and ethnicity. We estimated prevalence and used logistic regression examining risk factors of age, sex and socioeconomic status (SES) to compare prevalence of 252 physical and mental health conditions and 23 higher level health condition groups in adults with AF compared with adults without AF. RESULTS: 34 338 adults with AF (57% male; 83% ≥65 years) and 907 739 without AF (49% male; 23% ≥65 years) were identified. Adjusted for age and sex, adults with AF were significantly more likely to have 20/23 (87%) health condition groups than adults without AF. The most prevalent health condition groups in adults with AF were cardiovascular (prevalence of 89% in adults with AF vs 26% in adults without AF, adjusted OR (aOR) 5.82, 95% CI 5.60 to 6.05), gastrointestinal (62% vs 37%, aOR 1.34, 95% CI 1.31 to 1.38) and orthopaedic (58% vs 24%, aOR 1.32, 95% CI 1.29 to 1.35). 151/252 individual conditions were significantly more common in adults with AF including cardiovascular conditions such as cardiomyopathy (4.5% vs 0.3%, aOR 9.58, 95% CI 8.88 to 10.35) and heart failure (18% vs 0.7%, aOR 9.07, 95% CI 8.70 to 9.46), and non-cardiovascular conditions such as pleural effusion (16% vs 1.8%, aOR 3.55, 95% CI 3.42 to 3.67) and oesophageal malignancy (0.3% vs 0.0%, aOR 2.14, 95% CI 1.69 to 2.70). Associations were similar after SES adjustment. CONCLUSIONS: While cardiovascular conditions are highly prevalent and strongly associated with AF, a wide spectrum of non-cardiovascular conditions were also strongly associated, requiring a greater understanding of managing comorbid conditions with management principles contradictory to AF.

Humans↗

PubMedDate not supplied

Population-based cervical screening with a 5-year interval in The Netherlands. Stabilization of the incidence of squamous cell carcinoma and its precursor lesions in the screened population.

OBJECTIVE: To evaluate the outcome of population-based cervical screening at 5-year intervals. STUDY DESIGN: Results from the west region of the Netherlands (population 2 million) were used. The 1995-2000 round was compared with the first 2 years of the second (2001-2002). All results were prospectively collected in a central database. Positive cytologies and histoscores per 1,000 screened for preinvasive squamous cervical intraepithelial neoplasia (CIN) lesions and invasive squamous cell carcinoma were calculated. RESULTS: In the first round, 378,081 women were screened; in the second round, 100,561 women were screened. In both rounds the youngest screenees had the highest cytoscores. Cytoscores in the first round did not differ significantly from those in the second. The histoscore for CIN 1 and 2 was 1.42 per 1,000 in the first round and 1.18 per 1,000 (NS, P < .01) in the second. The histoscore for CIN 3 was 2.07 per 1,000 in the first round and 2.13 per 1,000 (NS, P < .01) in the second. Histoscores for invasive squamous cell carcinoma remained virtually the same (0.16 per 1,000 in the first, 0.14 per 1,000 in the second round). CONCLUSION: Population-based screening at 5-year intervals in the Netherlands may result in stabilization of positive cytology and of the incidence of CIN and (histologic) invasive squamous cell carcinoma. The program seems more cost effective than that of 2 decades ago, with a screening interval of 3 years.

Adult↗

PubMed2006

Prevalence of arsenic exposure from drinking water and awareness of its health risks in a Bangladeshi population: results from a large population-based study.

We conducted a population-based prevalence survey in Araihazar, Bangladesh, to describe the distribution of arsenic exposure in a rural Bangladeshi population and to assess the population's awareness to this problem as well as to possible remediation options. Water samples from 5,967 contiguous tube wells in a defined geographic area were tested using laboratory-based methods. Additionally, for each well, the owner/caretaker (or a close relative) was interviewed regarding his or her awareness of the health consequences of As exposure. Arsenic exposure data and demographic characteristics for the 65,876 users of these wells were also collected from the 5,967 respondents. Among the 65,876 residents, more than half (54%) regularly consumed well water with an As concentration > or = 50 microg/L--above the acceptable government standard in Bangladesh. Respondents were 15-92 years of age, with an average age of 42 years, and 43% were male. Presence of awareness was significantly related to male sex, nonlabor head of household occupation, better housing, and having had the well tested for As concentration. Most respondents (92%) expressed a willingness to take steps to reduce their exposure, with switching to a safe well the most favored option (46.2%). Willingness to reduce exposure was positively related to awareness of the health risks of As. However, the association between awareness and switching to a safe well [odds ratio (OR) = 1.25; 95% confidence interval (CI), 1.01-1.54] was no stronger than the associations between awareness and using surface water (with or without treatments) (OR = 1.54; 95% CI, 1.22-1.95) or using an existing well after treatment or increasing the depth (OR = 1.34; 95% CI, 1.08-1.67). These findings suggest that health education programs may need to target individuals with lower socioeconomic status and that well switching should be encouraged with more appropriate health education. Increasing knowledge of the health consequences of As may be an important element in facilitating remediation.

Adolescent↗

PubMed2005

Difficulties identifying and targeting COPD and population-attributable risk of smoking for COPD: a population study.

STUDY OBJECTIVES: Respiratory public health interventions depend on accurate identification of the target group, yet this may vary depending on the diagnostic criteria used. We therefore compared the relative performance of various international criteria in identifying COPD cases. The burden of COPD due to smoking can only be determined from population-attributable risk (PAR) studies. These studies, lacking in the COPD literature, are necessary research in support of public health initiatives for COPD. In this representative population study, we also assessed the PAR for current and ex-smokers. DESIGN: A representative biomedical population sample of 2,501 South Australians aged > or = 18 years (The Northwest Adelaide Health [Cohort] Study). COPD diagnosis and severity were determined according to various FEV1/FVC and FEV1 percentage of predicted criteria recommended by international respiratory authorities. Demographic, health behavior, and quality-of-life data were obtained by telephone interview and self-completed questionnaire. SETTING: Northwest Adelaide. MEASUREMENTS AND RESULTS: The PAR of smoking (smokers and ex-smokers) for COPD ranged from 51 to 70% depending on the diagnostic respiratory criteria used. COPD prevalence varied depending on the criteria used: American Thoracic Society, 5.4%; British Thoracic Society, 3.5%; European Respiratory Society (ERS), 5.0%; Global Initiative for Chronic Obstructive Lung Disease, 5.4%. There was also substantial disagreement in the cases identified. An alternative approach using ERS reference values one residual SD from the mean produced a COPD prevalence estimate of 6.9%, with improved level of agreement with the established respiratory criteria suggesting their potential as screening criteria. CONCLUSIONS: The COPD risks associated with smoking and ex-smoking history were quantifiable using PAR, but PAR also suggests other, yet unquantified, risks. Targeting COPD cases for public health interventions is difficult given the range of spirometry criteria and the associated high level of underdiagnosis.

Adult↗

PubMed1999

Low levels of serum calcidiol in an African population compared to a North European population.

OBJECTIVE: To compare vitamin D status in an African population living at 10 degrees N with a Norwegian population living at 60 degrees N. DESIGN: Serum samples from 30 healthy young Ethiopians and 31 full term pregnant women from Addis Ababa were collected in September, and from 24 healthy Norwegians in March and 23 pregnant women from Oslo in February to June. METHODS: Serum (s) levels of calcidiol and intact parathyroid hormone (iPTH) were measured. RESULTS: The median values for s-calcidiol were significantly lower in Ethiopians compared with Norwegians (young Ethiopians 23.5nmol/l vs young Norwegians 81nmol/l, P<0.001; pregnant Ethiopians 25nmol/l vs pregnant Norwegians 36nmol/l, P<0.05) while those for s-iPTH were significantly higher (young Ethiopians 5.7pmol/l vs young Norwegians 2.4pmol/l, P<0.001; pregnant Ethiopians 4.8pmol/l vs pregnant Norwegians 2.8pmol/l, P<0.02). CONCLUSION: In spite of abundant availability of ultraviolet radiation, the population from Addis Ababa had a high rate of biochemical vitamin D deficiency compared with the Norwegian group.

Adult↗

PubMed2004

An evidence of stromal cell populations functionally linked with epithelial cell populations in the mouse oviduct.

The oviductal epithelium consists of two major cell populations, secretory cells and cilial cells. In a previous report, we established clonal cell lines from the epithelium and stroma of an oviduct which allowed us to analyze stromal contribution to epithelial functions. Three stromal cell lines were co-cultured in separated apparatus with 3 epithelial cell lines, respectively. Two stromal cell lines preferentially stimulated mogp-1 expression on secretory cells and the stimulation was additive with estrogen. The lines had no effect on cilial cells. One stromal cell line preferentially stimulated foxj1 expression on cilial cells and the stimulation relieved suppression by estrogen. The line had no effect on secretory cells. Experiments with conditioned media of the stromal cells confirmed the results of co-culture experiments, suggesting that the oviductal stroma contains multiple cell populations preferentially regulating or modulating specific cell populations of the epithelium via diffusible factors.

Analysis of Variance↗

PubMed2005

Hypertension prevalence, awareness, treatment, and control in an adult type 1 diabetes population and a comparable general population.

OBJECTIVE: To compare the prevalence, awareness, treatment, and control of hypertension in a population-representative sample of adults with type 1 diabetes and comparable nondiabetic control subjects. RESEARCH DESIGN AND METHODS: In 2000-2002, the Coronary Artery Calcification in Type 1 Diabetes Study enrolled 1,416 individuals aged 19-56 years with no known history of coronary artery disease: 652 type 1 diabetic patients (46% male, mean age 37 years) and 764 nondiabetic control subjects (50% male, mean age 39 years). Subjects were asked if they had been told by a physician that they had hypertension or were on a blood pressure medication. Blood pressure was measured using standardized Joint National Committee (JNC) protocol. RESULTS: Type 1 diabetic subjects, compared with nondiabetic subjects, had higher rates of hypertension prevalence (43 vs. 15%, P < 0.001), awareness (53 vs. 45%, P = 0.11), treatment (87 vs. 47%, P < 0.001), and control (55 vs. 32%, P < 0.001) for the JNC 6 goal (130/85 mmHg). Only 42% of all type 1 diabetic hypertensive subjects met the new JNC 7 goal (130/80 mmHg). Type 1 diabetic subjects had better blood pressure control (72 vs. 32%, P < 0.0001), using 140/90 mmHg as a common measure. The majority of treated subjects were on a single antihypertensive agent (75 vs. 64%). CONCLUSIONS: Subjects with type 1 diabetes have higher rates of hypertension prevalence, treatment, and control than nondiabetic subjects. However, hypertension remains largely uncontrolled, even if treated in high-risk populations, such as type 1 diabetic subjects and undiagnosed individuals in the general population. Achieving more stringent blood pressure goals will require increased attention and may necessitate the use of multiple antihypertensive agents.

Adult↗

PubMed1998

[Analysis on the risk factors in patients with diabetes mellitus from population in mining districts--a population-based case-control study].

According to data from prevalence study on population from Pingdingshan coal mining districts in Henan province, we analysed 174 patients with diabetes mellitus(DM) and 3,066 control subjects with normal blood glucose(NGT) by a population-based case-control study. After the adjustment of other factors and controlled on confounding factors, the results of unconditional logistic multivariate regression analysis demonstrated that age, DM history of mother and sib, highest BMI through one's life, higher concurrent WHR, higher systolic blood pressure, frequently eating Chinese sorghum and legume may serve as independent risk factors of DM, their odds ratios(OR) were 2.04, 6.04, 2.24, 1.85, 2.57, 1.51, 2.22, 1.25 and their population attribution rates (PAR%) were 80.04%, 7.19%, 3.18%, 37.35%, 48.80%, 8.15%, 3.20%, 10.63% respectively. Higher occupational physical activity and frequently eating vegetables of light colour might serve as independent protective factors of DM, with ORs 0.89 and 0.50 and PAR% of -19.20% and -269.5% respectively. Confounding analysis showed that age was both a positive and negative confounding factor to other factors in the logistic regression model.

Adult↗

PubMed2003

Over 8 hours of sleep--marker of increased mortality in Mediterranean population: follow-up population study.

AIM: To investigate night and total sleep duration in relation to all-cause, cardiovascular, and non-cardiovascular mortality, controlling for recognized predictors of mortality in a population where the practice of siesta is common. METHODS: Our community-based sample included 1,842 residents (1,001 women) of a West Jerusalem neighborhood, aged 50 years and over. The study was conducted in the 1985-87 period, with a response rate of 85%. The participants were followed-up for 9-11 years. At the beginning of the study, the participants were asked at what time they usually fell asleep at night and awoke in the morning, and the average duration of their daytime nap if they slept during the day. Cox survival analysis was used to predict time to death for all-cause, cardiovascular, and non-cardiovascular mortality. RESULTS: The overall number of deaths was 403 (205 women), which included 170 deaths from cardiovascular causes (93 women). Men who reported long total sleep duration (>8h) had a substantially elevated risk of all-cause mortality (adjusted hazard ratio, 2.1; 95% confidence interval [CI], 1.2-3.7), and a stronger association with cardiovascular mortality (hazard ratio, 2.9; 95% CI, 1.2-7.1). The population attributable risk associated with more than 8 h of sleep was 12% (95% CI, 4-21%) for total mortality and 17% (95% CI, 4-33%) for cardiovascular causes of death. There was no significant association in women, although those who slept 6-8 h seemed to have the lowest risk. CONCLUSION: Duration of sleep is an important risk marker of mortality also in populations that practice afternoon siesta.

Aged↗