Browsing by Author "Madeira, Sara Alexandra Gamboa"
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- Circadian misalignment and cardiovascular health, from shift work to social jetlag : a chronotype based approachPublication . Madeira, Sara Alexandra Gamboa; Moreira, Carlos Manuel dos Santos; Paiva, Maria Teresa Aguiar dos Santos; Silva, Maria Cristina Monteiro Saraiva Guimarães Vaz daCircadian rhythms (from the Latin circa diem meaning “about a day”) are biological cycles endogenously generated. These rhythms are self-sustained, have a period of approximately 24h and are generated by an internal biological master clock, which entrains (synchronizes) to environmental cues. The 24h light–dark cycle, resulting from the Earth's rotation on its own axis, is the major synchronizer shaping several aspects of physiology and behavior of species from all phyla. Individual differences in how the human biological clock entrains to the 24h day – earlier or later, (e.g., in reference to dawn) – are expressions of different chronobiological traits (i.e., chronotypes). Chronotype ranges from extreme early/morning-types to extreme late/evening-types (the colloquial larks and owls), with the majority of people standing in between, presenting an approximately Gaussian distribution in the population. The Munich ChronoType Questionnaire (MCTQ) estimates chronotype through individuals’ sleep phase, assessing current sleep–wake behavior separately for work and work-free days. An MCTQ-derived chronotype is a continuous variable expressed in local time, the Midpoint of Sleep on Free days, corrected for sleep debt accumulated through weekdays (MSFsc). In addition to chronotype, MCTQ estimates the amount of strain on the biological circadian system exerted by social commitments, measured as the Social JetLag (SJL). SJL is a continuous variable expressed in hours and it is considered a proxy (and a quantitative marker) for the circadian misalignment. Circadian misalignment can emerge as a consequence of social obligations when there is a discrepancy between the internal sleep window (mostly driven by chronotype) and the social sleep opportunity (mostly driven by working schedules). Circadian misalignment can be transient, such as in transmeridian travels (i.e., jetlag) but it can be chronic, such as in shift work. Shift work affects more than 20% of the European workforce and has long been associated with an increased risk for chronic diseases and injuries. Major pathophysiological mechanisms that explain this link include circadian misalignment, sleep disturbances, unhealthy behaviors and psychosocial stress. The association between shift work and cardiovascular diseases has been researched for more than two decades and one systematic review showed that shift work was associated with a 23% increased risk of ischemic heart disease and 5% for stroke. Cardiovascular diseases are a major cause of morbidity and mortality in modern societies and guidelines on cardiovascular prevention stress the importance of non-traditional risk factors, such as occupational factors. Therefore, innovative ways to address cardiovascular health, especially among working adults are needed. To date, knowledge about the health impact of circadian misalignment and the role of the chronobiological inter-individual differences in real-life working settings is scarce. This thesis aims to improve knowledge in this field by revising the evidence concerning the cardiovascular consequences of different types of shift work and by exploring the role of social jetlag in the cardiovascular risk of shift workers. To achieve this aim, three studies were performed: Study 1 aimed to review and synthesize the existing scientific literature concerning the impact of different types of shift work both on systolic and diastolic blood pressure values and in the hypertension risk of shift workers, in comparison with day workers. A systematic review and meta-analysis were performed according to the PRISMA guidelines. Forty-five independent studies assessing ~117 thousand workers were included. The most frequent shift work type was “rotational shifts including night work” (n=28), followed by “permanent night work” (n=14) and “rotational shifts without night work” (n=4). Meta analysis pooled results reveal that: 1) permanent night workers had a significant increase in both systolic and diastolic blood pressure values; 2) rotational shift workers, both with and without night work, had a significant increase, only in systolic blood pressure; 3) no shift work type significantly influenced the risk of hypertension. The magnitude of the effect was rather small, ranging from 0.65 to 2.52 mmHg, and the larger upper bound of the pooled confidence intervals was 4.29 mmHg. This might seem not clinically significant, however, it should be considered in susceptible populations continuously exposed over a long period of time to shift work, as a possible contributing factor for the development of hypertension and/or for the need of more intensive drug treatment. Moreover, these results highlight the heterogenous aspect of shift work as a potential risk factor and reinforces the need for a more tailored assessment of the potential risks associated with shift work exposure. Study 2 aimed to validate the European Portuguese variant of the Munich Chronotype Questionnaire (MCTQ) to the adult population living in Portugal, using subjective and objective measures. We made the cross-cultural adaptation of the original MCTQ to develop the Portuguese variant (MCTQPT), and we explore its psychometric properties. A cross-sectional observational study including 80 volunteers (age and gender balanced according to the Portuguese distribution) filled out the MCTQPT and used actimetry for 4 weeks to objectively assess the sleep–wake cycle. Additionally, we compared MCTQPT results to the most widely used chronotyping questionnaire (i.e., MEQ. Results show that MCTQ key variables correlated highly with their counterparts calculated from actimetry (MSW: rho = 0.697; MSF: rho = 0.747; MSFsc: rho = 0.646; SJL: rho = 0.452; all p < 0.001). The MCTQ assessment of the chronotype showed very good test–retest reliability (rho = 0.905; p< 0.001). Therefore, MCTQPT proved to be a simple and valid instrument to assess chronotype and social jetlag among the Portuguese population. Study 3 aimed to investigate the association between social jetlag, as a measure of circadian misalignment, and cardiovascular risk, estimated from modifiable risk factors in a population of blue-collar workers following permanent atypical schedules. A cross-sectional observational study including 301 workers, who either worked morning, evening, or night shifts, filled out the MCTQPT and had major risk factors measured (blood pressure, total cholesterol, and smoking status) to estimate the cardiovascular relative risk SCORE. Our results showed that higher levels of social jetlag were associated with worse cardiovascular parameters. A higher degree of social jetlag was independently associated with greater odds of having a high cardiovascular relative risk, even after adjusting for sociodemographic, lifestyle, sleep, and work variables. This risk increased 31% for each additional hour of social jetlag that the worker is exposed to (odds ratio 1.31, 95% confidence interval 1.02– 1.68). Additionally, higher levels of working productivity were found among workers with less amount of social jetlag. To our knowledge, this was the first study indicating that social jetlag potentially increases cardiovascular risk and suggests that sleep and individual circadian traits (i.e., chronotype) are conceivably useful in preventing the health consequences of shift work. Our results support interventional studies on optimizing working schedules, that is, to test if the allocation of working schedules in accordance with the worker’s chronotype (e.g., early chronotypes are assigned to early shifts) have favorable results in both health and corporate outcomes. We conclude that the health consequences of shift work depend on both the characteristics of the work schedule and the individual chronobiological characteristics of the person who performs it. Effective ways to improve health and performance of shift workers are pressing and the solution might rely on the diversity of human chronotypes.
- A digital tool for self-reporting cardiovascular risk factors: the RADICAL studyPublication . Ferreira Santos, José; Castela, Inês; Madeira, Sara Alexandra Gamboa; Furtado, Sofia; Vieira Pereira, Hugo; Teixeira, Diana; Dores, HélderAims: Cardiovascular diseases remain the leading cause of death worldwide. Risk stratification and early interventions are essential to overcome this reality. The RADICAL Study ( R isk A ssessment via D igital I nput for C ardiovascular A nd L ifestyle Factors) aimed to evaluate the prevalence of self-reported cardiovascular risk factors in individuals without known cardiovascular disease using a digital tool. Methods and results: A digital self-reported cardiovascular risk stratification tool, comprising 23 questions about classical and lifestyle cardiovascular risk factors, was completed by 4149 individuals aged 40-69 years (median age 53.0 [47.0; 60.0] years; 78 % women). Among the cardiovascular risk factors, 40.9 % reported hypercholesterolemia, 26.8 % hypertension, 17.3 % smoking, 5.8 % diabetes, 58.4 % physical inactivity, 19.4 % obesity, 33.7 % sleep less than 7 h/night, and 12.1 % had composite dietary risk factors. Most of the participants (89.9 %) referred having at least one of the eight cardiovascular risk factors. Women had 27 % higher odds of having at least one cardiovascular risk factor compared to men (OR = 1.27, 95 % CI [1.00, 1.60]). Participants aged 50-59 years also had higher odds of having at least one CV risk factor compared to those aged 40-49 years (OR = 1.35, 95 % CI [1.07, 1.70]). Conclusion: The RADICAL Study reveals a high prevalence of cardiovascular risk factors in adults without known cardiovascular disease. Beyond the relevance of traditional risk factors, such as hypercholesterolemia and hypertension, the results regarding physical activity, dietary and sleeping habits are concerning. A self-reported cardiovascular risk identification digital tool could be feasible and help to improve cardiovascular prevention.
- Social jetlag, a novel predictor for high cardiovascular risk in blue‐collar workers following permanent atypical work schedulesPublication . Madeira, Sara Alexandra Gamboa; Reis, Cátia; Paiva, Teresa; Santos Moreira, Carlos; Nogueira, Paulo Jorge; Roenneberg, TillCardiovascular diseases cause >4 million deaths each year in Europe alone. Preventive approaches that do not only consider individual risk factors but their interaction, such as the Systematic COronary Risk Evaluation (SCORE), are recommended by European guidelines. Increased cardiovascular risk is associated with shift-work, surely interacting with the concurrent conditions: disruption of sleep, unhealthy behaviours, and circadian misalignment. Social jetlag (SJL) has been proposed as a way to quantify circadian misalignment. We therefore investigated the association between SJL and cardiovascular health in a cross-sectional observational study involving blue-collar workers, who either worked permanent morning, evening, or night shifts. Sociodemographic, health and productivity data were collected through questionnaires. Blood pressure and cholesterol were measured and the cardiovascular risk was estimated according to the relative risk SCORE chart. Bivariate analysis was performed according to the cardiovascular risk and the relationship between SJL and high cardiovascular risk was analysed through logistic regression. Cumulative models were performed, adjusted for various confounding factors. After 49 exclusions, the final sample comprised 301 workers (56% males; aged <40 years, 73%). Mean standard deviation (SD) SJL was 1:57 (1:38) hr (59.4% ≤2 hr). Cardiovascular risk was high in 20% of the sample. Multivariate analysis revealed SJL to be an independent risk factor for high cardiovascular risk. Each additional hour of SJL increased this risk by >30% (odds ratio 1.31, 95% confidence interval 1.02-1.68). This is the first study indicating that SJL potentially increases cardiovascular risk, and suggests that sleep and individual circadian qualities are critical in preventing negative health impacts of shift-work.
- Sofrimento psicológico, consumo de tabaco, álcool e outros fatores psicossociais em adolescentes portuguesesPublication . Cerqueira, Ana; Gaspar, Tania; Guedes, Fábio Botelho; Madeira, Sara Alexandra Gamboa; Matos, Margarida Gaspar deThe purpose of this study was to analyze the influence of tobacco, alcohol and social factors (communication with parents, relationships with friends and liking school) on psychological factors as well as differences in gender and school years. The sample consisted of adolescents who participated in the Health Behaviour in School-aged Children (HBCS) study, in 2018, in Portugal and had the participation of 8215 adolescents of the 6th, 8th, 10th and 12th grades, being 52,7% females, with a mean age of 14.36 years (SD=2,18). The results showed that adolescents who have good communication with parents and who like school show fewer psychological symptoms. On the other hand, a bad relationship with friends arises related to an increase in psychological symptoms. The consumption of tobacco and alcohol did not present differences of gender, however they vary according to the school year and relate negatively to psychological symptoms. The results found reinforce the importance of communication and relationship with parents as protective factors and demonstrate that the relationship with friends can be a protective factor for wellbeing. It is therefore crucial to simultaneously help young people to develop strategies to minimize potential adverse effects of this relationship, in particular as regards peer pressure and consequently reduce their impact on their physical and mental health.
- The impact of different types of shift work on blood pressure and hypertension: a systematic review and meta-analysisPublication . Madeira, Sara Alexandra Gamboa; Fernandes, Carina; Paiva, Teresa; Santos Moreira, Carlos; Caldeira, DanielShift work (SW) encompasses 20% of the European workforce. Moreover, high blood pressure (BP) remains a leading cause of death globally. This review aimed to synthesize the magnitude of the potential impact of SW on systolic blood pressure (SBP), diastolic blood pressure (DBP) and hypertension (HTN). MEDLINE, EMBASE and CENTRAL databases were searched for epidemiological studies evaluating BP and/or HTN diagnosis among shift workers, compared with day workers. Random-effects meta-analyses were performed and the results were expressed as pooled mean differences or odds ratios and 95% confidence intervals (95% CI). The Newcastle-Ottawa Scale was used to assess the risk of bias. Forty-five studies were included, involving 117,252 workers. We found a significant increase in both SBD and DBP among permanent night workers (2.52 mmHg, 95% CI 0.75-4.29 and 1.76 mmHg, 95% CI 0.41-3.12, respectively). For rotational shift workers, both with and without night work, we found a significant increase but only for SBP (0.65 mmHg, 95% CI 0.07-1.22 and 1.28 mmHg, 95% CI 0.18-2.39, respectively). No differences were found for HTN. Our findings suggest that SW is associated with an increase of BP, mainly for permanent night workers and for SBP. This is of special interest given the large number of susceptible workers exposed over time.
- Validation of the Portuguese variant of the Munich Chronotype Questionnaire (MCTQPT)Publication . Reis, Cátia; Madeira, Sara Alexandra Gamboa; Lopes, Luísa; Paiva, Teresa; Roenneberg, TillIntroduction: Differences in the manner circadian clocks entrain to the 24-h day are expressions of different chronotypes that can range from extreme early to extreme late, from proverbial larks to owls. The Morningness Eveningness Questionnaire (MEQ) was one of the first to assess daily preference based on subjective self-assessment – a psychological construct. The later developed Munich Chronotype Questionnaire (MCTQ) uses instead the actual sleep timing to assess chronotype. It calculates the midsleep point, halfway between onset and offset on work-free days (MSF), which is then corrected for potential oversleep on free days compensating for sleep debt accumulated over the workweek (MSFsc). MSFsc is expressed in local time and is thought to be a proxy for “phase of entrainment” of the circadian clock. The MCTQ-derived chronotype is therefore a biological construct. In the present report, we validate the Portuguese variant (MCTQPT) of the MCTQ. Portugal is of particular interest, since it is thought to consist of especially late chronotypes. Methods: We have used three methods to assess the timing of daily behavior, namely, the chronotype (MCTQ), the daily preference (rMEQ), and a simple self-assessment (time-of-day type). A total of 80 healthy adults living in Portugal, with age and sex distributed according to the Portuguese population, were recruited. We analyzed 4 weeks of continuous records of actimetry data to validate the MCTQPT and used the rMEQ to compare between a biological chronotype (sleep timing) and a psychological chronotype (daily preference). MCTQ variables were analyzed by descriptive statistics; correspondence between measurements was done by Spearman correlations or cross-tabulation; in a subset of 41 individuals, test–retest reliability was assessed. Results: MCTQ-derived variables (MSF, MSW, MSFsc) correlated highly with their counterparts calculated from actimetry (MSW: rho = 0.697; MSF: rho = 0.747; MSFsc: rho = 0.646; all p < 0.001). The MCTQ assessment of the chronotype showed good test–retest reliability (rho = 0.905; p < 0.001). The rMEQ score correlates with MSFsc (rho = −0.695; p < 0.001), and the agreement for the self-assessment with the MSFsc was fair (kw = 0.386; p < 0.001). Conclusion: The Portuguese variant of the MCTQ revealed to be a reliable questionnaire to assess the chronotype for the Portuguese adult population, as previously reported for other countries.