Cohort profile: The Limache, Chile, birth cohort study

Depression symptoms are associated with demographic characteristics, nutritional status, and social support among young adults in Chile: a latent class analysis

BACKGROUND

Depressive disorders are a critical public health concern in Chile. Nonetheless, there is a lack of evidence regarding the identification of depressive symptom clusters. The objective was to identify depressive symptom clusters among Chilean young adults and examine how demographic, and lifestyle factors as well as social support can influence and predict them.

METHODS

Cross-sectional study conducted among 1,000 participants from the Limache cohort 2. A latent class analysis (LCA) was performed to identify depressive symptom clusters, using the Patient Health Questionnaire (PHQ-9). Multinomial logistic regression was then applied to explore the associations between identified classes and potential predictors. The models were adjusted by age and sex.

RESULTS

Three latent classes of depressive symptoms were identified: minimal (25.7%); somatic (50.7%) and severe (23.6%). In the severe class for eight out nine depressive symptoms the probabilities were above 50%, and the probability of suicidal ideation was almost a third in this class. Being female (Adjusted Odds ratio [AOR], 2.49; 95% confidence interval [CI] [1.63-3.81]), current smoker (AOR, 1.74; 95% CI [1.15-2.65]), having basic education (AOR, 3.12; 95% CI [1.30-7.53]) and obesity (AOR, 2.72; 95% CI [1.61-4.59]) significantly increased the likelihood of belonging to severe class. Higher social support decreased the odds of being in the somatic (OR, 0.96; 95% CI [0.93-0.98]) and severe (OR, 0.92; 95% CI [0.90-0.94]) classes.

CONCLUSIONS

These findings highlight the importance of individualized intervention strategies for depression management. Also, the study suggests that nutritional status and social support should be considered when addressing depression in this population.

Usefulness of SPISE Index for Screening and Detection of Early Stages of Insulin Resistance among Chilean Young Adults

BACKGROUND

As the gold standard test to quantify insulin resistance (IR) involves intravenous insulin loading and repeated blood glucose monitoring, many indexes have been developed for IR assessment for convenience.

OBJECTIVE

The objective of this study was to evaluate the agreement of the Single-Point Insulin Sensitivity Estimator (SPISE) by comparing it with the homeostasis model assessment of insulin resistance (HOMA-IR) in identifying IR.

METHOD

Data came from the ongoing LIMACHE BIRTH COHORT. 1,948 individuals (aged 22-28 years) were studied. We performed an agreement plot called a Bangdiwala's Observer Agreement to evaluate patterns in departures from agreement in ordinal categorical variables.

RESULTS

According to the Bangdiwala-Weighted statistics, we found that the agreement between both indexes was 0.14; this value would be considered a slight agreement. Thus, we found bias in the marginal distributions, and we noticed that the SPISE has a bias toward the central quintiles of the index.

CONCLUSIONS

The identification of IR in young adult individuals by the SPISE index has slight agreement with HOMA-IR. Therefore, caution would be taken when considering SPISE index among young Chilean adults.

When a birth cohort grows up: challenges and opportunities in longitudinal developmental origins of health and disease (DOHaD) research

High-quality evidence from prospective longitudinal studies in humans is essential to testing hypotheses related to the developmental origins of health and disease. In this paper, the authors draw upon their own experiences leading birth cohorts with longitudinal follow-up into adulthood to describe specific challenges and lessons learned. Challenges are substantial and grow over time. Long-term funding is essential for study operations and critical to retaining study staff, who develop relationships with participants and hold important institutional knowledge and technical skill sets. To maintain contact, we recommend that cohorts apply multiple strategies for tracking and obtain as much high-quality contact information as possible before the child's 18th birthday. To maximize engagement, we suggest that cohorts offer flexibility in visit timing, length, location, frequency, and type. Data collection may entail multiple modalities, even at a single collection timepoint, including measures that are self-reported, research-measured, and administrative with a mix of remote and in-person collection. Many topics highly relevant for adolescent and young adult health and well-being are considered to be private in nature, and their assessment requires sensitivity. To motivate ongoing participation, cohorts must work to understand participant barriers and motivators, share scientific findings, and provide appropriate compensation for participation. It is essential for cohorts to strive for broad representation including individuals from higher risk populations, not only among the participants but also the staff. Successful longitudinal follow-up of a study population ultimately requires flexibility, adaptability, appropriate incentives, and opportunities for feedback from participants.

Low and insufficient birth weights as important factors of developmental stages of type 2 diabetes: Intergenerational Limache Cohort study

BACKGROUND & AIMS

This study aimed to investigate the association of birth weight with developmental stages of Type 2 Diabetes among Chilean young adults.

METHODS

A probabilistic sample of 1947 individuals (22-28 years) that belong to two birth cohorts (cohort 1: participants born in 1974-1978, cohort 2: participants born in 1988-1992). Multivariable logistic regressions were calculated.

RESULTS

Birth weight was negatively associated with insulin resistance (IR) and dysglycaemia (prediabetes and diabetes) in adulthood (adjusted odds ratio [AOR]: 0.76 (95% confidence interval [CI]: 0.61-0.94), OR: 0.72 (95% CI: 0.60-0.89) for IR and IR plus dysglycaemia, respectively. The AOR for IR plus dysglycaemia for males was 0.72 (95% CI: 0.51-0.99) and for females was 0.77 (95% CI: 0.60-1.01). Birth weight below 3.0 kg (Cohort 2) was associated with 1.40 (95% CI: 1.01-1.95) higher likelihood of IR plus dysglycaemia.

CONCLUSIONS

Our results demonstrate how a population of young adults experienced greater probability of IR, impaired fasting glucose, and diabetes as birth weight decreases. We report a novel finding of effect of suboptimal birth weight on metabolic alterations that belongs to developmental stages of Type 2 Diabetes in young adults born in a period of epidemiological and nutrition transition and grew in post-transition.

Undernutrition and suboptimal growth during the first year are associated with glycemia but not with insulin resistance in adulthood

This study aimed to assess whether weight, length, and conditional growth during the first year are associated with glycemia and insulin resistance among young adults. A non-concurrent longitudinal design was used in the study. This is a population-based cohort study, composed of people aged from 22 to 28 years. We estimated z-scores from birth to the first year and the infants were classified as stunted, underweight, overweight, obese, wasted, and at risk of wasting, using cut-offs proposed by the World Health Organization (Child Growth Standards, 2006). Conditional weight and length gain variables were estimated. Glycemia, insulin, homeostasis model assessment of insulin resistance (HOMA-IR), and single point insulin sensitivity estimator (SPISE) were evaluated in adulthood. Multiple linear regressions that includes the variables associated with glycemia and insulin resistance were used. In total, 1,070 subjects were evaluated and glycemia in adulthood was higher among subjects who were wasted or at risk of wasting at 12 months (β coefficient = 2.77; 95%CI: 0.37; 5.21). In relation to normal weight, those subjects who were overweight at 12 months showed the lowest glycemia (β coefficient = -2.39; 95%CI: -4.32; -0.36). Conditional weight gain in the first year was negatively associated with glycemia in adulthood (β coefficient = -0.65; 95%CI: -1.23; -0.08). SPISE was higher among underweight subjects, and negatively associated with conditional relative weight gain and conditional linear growth in the first year. In conclusion, we found that undernutrition and suboptimal growth were associated with higher glycemia.

Changes in socio-economic level and their impact on nutritional status: a follow-up study among young Chilean adults

Objective

To verify the association between changes in socio-economic level (SEL) and nutritional status of Chilean adults over a 10-year period.

Design

Concurrent cohort study.

Setting/Subjects

Individuals born from 1974 to 1978 in the Valparaíso Region of Chile were evaluated between 2000 and 2002 (n 1232) and again between 2010 and 2012 (n 796). SEL was characterized according to the occupation and educational level of the head of household. Nutritional status was based on measurement of BMI and waist circumference (WC).

Results

Between the first and second evaluation there was a 13 % reduction in the number of individuals classified as poor and a 12 % increase in those classified in the medium high SEL. Increases in BMI were found among women who remained in the low SEL (β=2·2, 95 % CI 0·16, 2·87) compared with women who maintained the same SEL (and whose SEL was above low over the 10-year period). Women who remained in the low SEL increased their WC (β=4·10, 95 % CI 0·27, 7·93). There were no associations between nutritional status and SEL among males.

Conclusions

In the period studied, the SEL of the study population improved between the third and fourth decade of life, but BMI and WC also increased among women, with the lowest socio-economic group experiencing the greatest changes. Meanwhile, among males we found no association between anthropometric measurements and changes in SEL.

Does the association between birth weight and blood pressure increase with age? A longitudinal study in young adults

OBJECTIVES

To assess whether the association between birth weight and blood pressure (BP) increases with age using three different statistical methods.

METHODS

A representative sample of 1232 study participants born between 1974-1978 in Limache, Chile were assessed in 2000-2002, of whom 796 were reassessed in 2010-2012. An 'amplification effect' was assessed by the change in the β coefficient in the two periods, the association between birth weight and the difference of BP overtime, and the interaction between birth weight and BP in the two periods.

RESULTS

Birth weight was negatively associated with SBP in 2000-2002 (β = -2.46, 95% confidence interval (CI) -3.77 to -1.16) and in 2010-2012 (β = -3.64, 95% CI -5.20 to -2.08), and with DBP in 2000-2002 (β = -1.26, 95% CI -2.23 to -0.29) , and 2010-2012 (β = -1.64, 95% CI -2.84 to -0.45) after adjustment for sex, physical activity, and BMI. There was no association between birth weight and the difference in BP between the two periods or the interaction between birth weight, BP, and time interval.

CONCLUSION

Birth weight is a factor associated with BP in adults. This association increased with age, but amplification was shown only with one of the three methods.

Changes in symptoms of asthma and rhinitis by sensitization status over ten years in a cohort of young Chilean adults

Background

We investigated the net changes in prevalence of symptoms of asthma and rhinitis over 10 years in a cohort of young by baseline sensitization status.

Methods

One thousand one hundred ninety three Chilean adults subjects aged 22–28 living in a semi-rural area of central Chile answered a lifestyle and the European Community Respiratory Health Survey (ECRHS) questionnaires. Bronchial hyper-responsiveness (BHR) and skin prick test (SPT) to eight allergens were measured at baseline in 2001. Ten years later, 772 participants completed the questionnaires again. Estimates of adjusted net changes in prevalence of symptoms by sensitization status at baseline and association between sensitization status at baseline and respiratory symptoms ten years later were assessed.

Results

A quarter of the participants were sensitized to at least one allergen in 2001. Prevalence of wheeze had a net change per year of −0.37 % (95 % Confidence Interval −0.71 to 0.02 %; p = 0.067). Self-reported nasal allergies in the last 12 months increased by 0.83 % per year (95 % CI 0.49 to 1.17 %; p < 0.001). Those sensitized to either cat fur (OR 1.76; CI 1.01 to 3.05), cockroach, (OR 2.09; 1.13 to 3.86) blend of grass and pollens (1.78; 95 % CI 1.08 to 2.92), or weeds (OR 1.77; 95 % CI 1.01 to 3.12) in 2001 were more likely to have wheeze in the last 12 months 10 years later.

Conclusion

Symptoms of asthma remained stable or slightly changed over 10 years in adults, whilst rhinitis and nasal allergies greatly increased. Being sensitized to at least one allergen is a risk factor for persistent symptoms of asthma and rhinitis, but not for determining net changes of symptoms over time. The underlying causes for the contrasting trends between asthma and nasal allergy are unknown.

Electronic supplementary material

The online version of this article (doi:10.1186/s12890-016-0273-6) contains supplementary material, which is available to authorized users.

[Secular variation of births, weight and length at birth: Local perspective]

OBJECTIVE

To analyse the outcomes of births and anthropometric measurements at birth of children born between 1974 and 2011 at Limache Hospital (Valparaíso, Chile).

PATIENTS AND METHOD

Times series were constructed of births, weight and length at birth, and low weight and length at birth. The trend was modelled with linear and logistical regressions using splines to represent breaks in the trend by decade.

RESULTS

The series includes 17,574 births. There was an increase in births per year in the 1970s (30/year) and declines in them to 17 and 22 births/year in the 1980s and 1990s, respectively (P<.001), with no significant trend thereafter. Newborns from 2000 to 2011 weighed 266 grams more than those in the 1970s (P<.001), and have now reached a mean weight of 3,530 g. Low birthweight fell from 8% in the 1970s to 1.1% after 2000. Birth length increased by 1cm in the 37 years studied, with a reduction of low birth length from 7.6% to 2.1% during the period.

CONCLUSION

Live births in the Limache Hospital declined, and anthropometric measurements at birth improved in the years analysed. This information is useful in developing interventions, taking into account the possible selection biases that could distort these estimates and their interpretation.

Ventilatory function in young adults and dietary antioxidant intake

Dietary antioxidants may protect against poor ventilatory function. We assessed the relation between ventilatory function and antioxidant components of diet in young Chileans. Forced expiratory volume in 1 s (FEV₁), forced vital capacity (FVC), and the ratio FEV₁/FVC were measured in 1232 adults aged 22–28 years, using a Vitalograph device. Dietary intake was ascertained with a food frequency questionnaire (FFQ) designed for this study, from which nutrient and flavonoid intakes were estimated. Dietary patterns were derived with Principal Component Analysis (PCA). After controlling for potential confounders, dietary intake of total catechins was positively associated with FVC (Regression coefficient (RC) of highest vs. lowest quintile of intake 0.07; 95% CI 0.01 to 0.15; p per trend 0.006). Total fruit intake was related to FVC (RC of highest vs. lowest quintile 0.08; 95% CI 0.003 to 0.15; p per trend 0.02). Intake of omega 3 fatty acids was associated with a higher FEV₁ (RC for highest vs. lowest quintile 0.08; 95% CI 0.01 to 0.15 L; p per trend 0.02) and with FVC 0.08 (RC in highest vs. lowest quintile of intake 0.08, 95% CI 0.001 to 0.16; p per trend 0.04). Our results show that fresh fruits, flavonoids, and omega 3 fatty acids may contribute to maintain ventilatory function.

Ventilatory function and cardiovascular disease risk factors: a cross-sectional study in young adults

Background

The association between impaired lung function and cardiovascular disease (CVD) risk factors has been shown in adults. However, there is little evidence of such an association in young adults, particularly from South America, where the burden of CVD and chronic obstructive pulmonary disease (COPD) is as high as that observed in more developed countries. We therefore investigated the relation between CVD risk factors including metabolic syndrome (MS), and lung function status in young adults from Chile.

Methods

970 subjects from a sample of 998 adults born between 1974 and 1978 in Limache, Chile, were studied. A Spanish translation of the European Community Respiratory Health Survey (ECRHS) questionnaire was used. Forced expiratory volume in 1 second (FEV₁) and forced vital capacity (FVC) were measured. Weight, height, waist circumference (WC), blood pressure, Homeostatic model assessment (HOMA-IR), triglycerides, high density lipoprotein (HDL), glycaemia, and metabolic syndrome (MS) were also assessed.

Results

The prevalence of MS was 11.8%. A lower FEV₁ and lower FVC were associated with having MS (β-coefficient -0.13; 95% Confidence Interval [CI] -0.21 to -0.05, and β-coefficient -0.18; 95% CI -0.27 to -0.09, respectively). Both spirometric measures were also negatively associated with having an elevated HOMA-IR (β-coefficient for FEV₁ -0.08; 95% CI -0.13 to -0.03, and β-coefficient for FVC -0.11; 95% CI -0.17 to -0.05). In males only, a lower FEV₁ and FVC were associated with having elevated triglycerides (β-coefficient highest vs. lowest tertile -0.13, 95% CI -0.24 to -0.03, and β-coefficient -0.13, 95% CI -0.25 to -0.01, respectively). In women, a higher FEV₁ and FVC were statistically significantly related to having higher levels of HDL. Ventilatory function was unrelated to hypertension or WC in this population.

Conclusion

In this population-based study of young adults, a poorer ventilatory function was associated with many CVD risk factors. Endeavours to understand better causality issues of such associations are warranted.