Incidence of type 2 diabetes after gastric by-pass surgery in a Swedish controlled cohort study

AIMS

To assess the long-term risk of developing type 2 diabetes in patients with obesity who have undergone gastric bypass surgery compared to non-operated patients with obesity and the general population.

METHODS

This study included 71,495 patients aged 20-65 years with a principal diagnosis of obesity in the Swedish Patient Register in 2001-2013. Of these, 23,099 had undergone gastric bypass and 32,435 had not. Each patient was matched by age, sex and geographic region with two controls from the general population without obesity diagnosis, i.e., 44,735 controls for the gastric bypass cohort and 62,522 controls for the non-operated cohort with obesity. Operated and non-operated patients with obesity were also directly compared using Cox regression analysis, providing hazard ratios (HR) with 95% confidence intervals (CI) adjusted for age, education, and sex.

RESULTS

During a median follow-up of 4.3 years (interquartile range [IQR] 2.4, 7.0 years), 3792 (11.7%) non-operated patients with obesity developed type 2 diabetes (incidence rate 22.8/1000 person-years, 95% CI 22.1-23.6) compared to 394 (1.7%) among gastric bypass patients (incidence rate 4.0/1000 person-years, 95% CI 3.6-4.5). The latter incidence was comparable to population controls (3.5/1000 person-years, 95% CI 3.2-3.8). Gastric bypass patients had 85% lower risk of diabetes compared to non-operated patients with obesity during the first six years of follow-up (HR 0.15; 95% CI 0.13-0.17).

CONCLUSION

Gastric bypass surgery for obesity seems to reduce the risk of developing type 2 diabetes to levels similar to that of the general population during the first six years of follow-up but not thereafter.

Age and sex differences in cause-specific excess mortality and years of life lost associated with COVID-19 infection in the Swedish population

BACKGROUND

Estimating excess mortality and years of life lost (YLL) attributed to coronavirus disease 19 (COVID-19) infection provides a comprehensive picture of the mortality burden on society. We aimed to estimate the impact of the COVID-19 pandemic on age- and sex-specific excess mortality and YLL in Sweden during the first 17 months of the pandemic.

METHODS

In this population-based observational study, we calculated age- and sex-specific excess all-cause mortality and excess YLL during 2020 and the first 5 months of 2021 and cause-specific death [deaths from cardiovascular disease (CVD), cancer, other causes and deaths excluding COVID-19] in 2020 compared with an average baseline for 2017-19 in the whole Swedish population.

RESULTS

COVID-19 deaths contributed 9.9% of total deaths (98 441 deaths, 960 305 YLL) in 2020, accounting for 75 151 YLL (7.7 YLL/death). There were 2672 (5.7%) and 1408 (3.0%) excess deaths, and 19 141 (3.8%) and 3596 (0.8%) excess YLL in men and women, respectively. Men aged 65-110 years and women aged 75-110 years were the greatest contributors. Fewer deaths and YLL from CVD, cancer and other causes were observed in 2020 compared with the baseline adjusted to the population size in 2020.

CONCLUSIONS

Compared with the baseline, excess mortality and YLL from all causes were experienced in Sweden during 2020, with a higher excess observed in men than in women, indicating that more men died at a younger age while more women died at older ages than expected. A notable reduction in deaths and YLL due to CVD suggests a displacement effect from CVD to COVID-19.

Prepregnancy overweight and obesity and long-term risk of venous thromboembolism in women

Overweight and obesity rates have increased in recent decades, particularly among the younger population. The long-term consequences of obesity with respect to early venous thromboembolism (VTE) in women have not been established. The aim was to investigate the association between body mass index (BMI) in early pregnancy as a proxy for non-pregnant weight and long-term post-pregnancy risk of VTE in women. This registry-based prospective cohort study analysed data from the Swedish Medical Birth Registry, linked to the National Patient and the National Cause of Death Registries for information on post-pregnancy long-term risk of VTE. Cox proportional hazards model were used to determine the association between BMI at baseline and VTE events during follow-up starting 1 year after baseline. The mean age at registration was 27.5 (standard deviation, 4.9) years. During a median follow-up duration of 12 years (interquartile range, 6-21 years) starting 1 year after the first antenatal visit, 1765 and 2549 women had a deep vein thrombosis and/or pulmonary embolism. The risk of VTE linearly increased with increasing BMI. Compared to women with 20 ≤ BMI < 22.5 kg/m2, women with high normal weight, i.e. with a BMI of 22.5-25.0 kg/m2, had an adjusted hazard ratio (HR) of 1.30 (95% confidence interval [CI] 1.19-1.41), whereas those with a BMI of 30-35 kg/m2 and ≥ 35 kg/m2 (severe obesity) had an adjusted HR of 2.35 (95% CI 2.04-2.70) and 3.47 (95% CI 2.82-4.25, respectively. Using BMI in early pregnancy as a proxy for pre-pregnancy or non-pregnant BMI in young women, we found a significantly increased risk of post-pregnancy long-term risk of VTE even in those with high normal BMI, compared with lean women, whereas those with severe obesity had a markedly high risk.

Pulmonary embolism and deep venous thrombosis after COVID-19: long-term risk in a population-based cohort study

Background

Venous thromboembolism (VTE) (pulmonary embolism (PE) or deep venous thrombosis (DVT)) is common during acute COVID-19. Long-term excess risk has not yet been established.

Objective

To study long-term VTE risk after COVID-19.

Methods

Swedish citizens aged 18-84 years, hospitalized and/or testing positive for COVID-19 between January 1, 2020, and September 11, 2021 (exposed), stratified by initial hospitalization, were compared to matched (1:5) non-exposed population-derived subjects without COVID-19. Outcomes were incident VTE, PE or DVT recorded within 60, 60-<180, and ≥180 days. Cox regression was used for evaluation and a model adjusted for age, sex, comorbidities and socioeconomic markers developed to control for confounders.

Results

Among exposed patients, 48,861 were hospitalized for COVID-19 (mean age 60.6 years) and 894,121 were without hospitalization (mean age 41.4 years). Among patients hospitalized for COVID-19, fully adjusted hazard ratios (HRs) during 60-<180 days were 6.05 (95% confidence interval (CI) 4.80─7.62) for PE and 3.97 (CI 2.96─5.33) for DVT, compared to non-exposed with corresponding estimates among COVID-19 without hospitalization 1.17 (CI 1.01─1.35) and 0.99 (CI 0.86─1.15), based on 475 and 2,311 VTE events, respectively. Long-term (≥180 days) HRs in patients hospitalized for COVID-19 were 2.01 (CI 1.51─2.68) for PE and 1.46 (CI 1.05─2.01) for DVT while non-hospitalized had similar risk to non-exposed, based on 467 and 2,030 VTE events, respectively.

Conclusions

Patients hospitalized for COVID-19 retained an elevated excess risk of VTE, mainly PE, after 180 days, while long-term risk of VTE in individuals with COVID-19 without hospitalization was similar to the non-exposed.

COVID-19 in people aged 18-64 in Sweden in the first year of the pandemic: Key factors for severe disease and death

Background

Studies on risk factors for severe COVID-19 in people of working age have generally not included non-working persons or established population attributable fractions (PAFs) for occupational and other factors.

Objectives

We describe the effect of job-related, sociodemographic, and other exposures on the incidence, relative risks and PAFs of severe COVID-19 in individuals aged 18-64.

Methods

We conducted a registry-based study in Swedish citizens aged 18-64 from 1 January 2020 to 1 February 2021 with respect to COVID-19-related hospitalizations and death.

Results

Of 6,205,459 persons, 272,043 (7.5%) were registered as infected, 3399 (0.05%) needed intensive care, and 620 (0.01%) died, with an estimated case fatality rate of 0.06% over the last 4-month period when testing was adequate. Non-Nordic origin was associated with a RR for need of intensive care of 3·13, 95%CI 2·91-3·36, and a PAF of 32·2% after adjustment for age, sex, work, region and comorbidities. In a second model with occupation as main exposure, and adjusted for age, sex, region, comorbidities and origin, essential workers had an RR of 1·51, 95%CI, 1·35-1·6, blue-collar workers 1·18, 95%CI 1·06-1·31, school staff 1·21, 95%CI 1·01-1·46, and health and social care workers 1·89, 95%CI 1·67-2·135) compared with people able to work from home, with altogether about 13% of the PAF associated with these occupations. Essential workers and blue-collar workers, but no other job categories had higher risk of death, adjusted RRs of 1·79, 95%CI 1·34-2·38 and 1·37, 95%CI 1·04-1·81, with adjusted PAFs of altogether 9%.

Conclusion

Among people of working age in Sweden, overall mortality and case fatality were low. Occupations that require physical presence at work were associated with elevated risk of needing intensive care for COVID-19, with 14% cases attributable to this factor, and 9% of deaths.

Severe COVID-19 in people 55 and older during the first year of the pandemic in Sweden

BACKGROUND

Exposure to many contacts is the main risk factor for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, while risk of serious disease and death is chiefly determined by old age and comorbidities. Relative and population-attributable fractions (PAFs) of multiple medical and social exposures for COVID-19 outcomes have not been evaluated among older adults.

OBJECTIVES

We describe the effect of multiple exposures on the odds of testing positive for the virus and of severe disease (hospital care or death) and PAFs in Swedish citizens aged 55 years and above.

METHODS

We used national registers to follow all citizens aged 55 years and above with respect to (1) testing positive, (2) hospitalization, and (3) death between 31 January 2020 and 1 February 2021.

RESULTS

Of 3,410,241 persons, 156,017 (4.6%, mean age 68.3 years) tested positive for SARS-CoV-2, while 35,999 (1.1%, mean age 76.7 years) were hospitalized or died (12,384 deaths, 0.4%, mean age 84.0 years). Among the total cohort, the proportion living without home care or long-term care was 98.8% among persons aged 55-64 and 22.1% of those aged 95 and above. After multiple adjustment, home care and long-term care were associated with odds ratios of 7.9 (95% confidence interval [CI] 6.8-9.1) and 22.5 (95% CI 19.6-25.7) for mortality, with PAFs of 21.9% (95% CI 20.9-22.9) and 33.3% (95% CI 32.4-34.3), respectively.

CONCLUSION

Among Swedish residents aged 55 years and above, those with home care or long-term care had markedly increased risk for COVID-19 death during the first year of the pandemic, with over 50% of deaths attributable to these factors.

Surgical treatment of obesity and excess risk of developing heart failure in a controlled cohort study

AIM

We aim to assess the risk of heart failure in patients with obesity with and without gastric bypass surgery compared with population controls.

METHODS AND RESULTS

This cohort study included all patients aged 20-65 years with a first ever registered principal diagnosis of obesity in the Swedish Patient Register in 2001-2013. These patients were matched by age, sex, and region with two population controls from the general Swedish population without obesity diagnosis. The obesity cohort was divided into two groups: 27 882 patients who had undergone gastric bypass surgery within 2 years of obesity diagnosis and 39 564 patients who had not undergone such surgery. These groups were compared with 55 149 and 78 004 matched population controls, respectively. Cox regression provided hazard ratios (HR) with 95% confidence intervals (CI), adjusted for age, education, and sex. During follow-up (maximum 10 years, median 4.4 years, and interquartile range 2.5-7.2 years), 1884 participants were hospitalized for heart failure. Compared with population controls, gastric bypass patients had no excess risk of heart failure during the initial 0-≤4 years of follow-up (HR = 1.35 [95% CI = 0.96-1.91]) but a marked increased risk during the final >4-10 years of follow-up (HR = 3.28 [95% CI = 2.25-4.77]). Non-operated patients with obesity had a marked excess risk of heart failure throughout the study period compared with population controls.

CONCLUSIONS

Gastric bypass for obesity seems to reduce the risk of heart failure to levels similar to the general population during the initial 4 years after surgery, but not thereafter.

Trends in survival of Swedish men and women with heart failure from 1987 to 2014: a population-based case-control study

AIMS

To compare trends in short-term and long-term survival of patients with heart failure (HF) compared with controls from the general population.

METHODS AND RESULTS

We used data from the Swedish National Inpatient Registry to identify all patients aged ≥18 years with a first recorded diagnosis of HF between 1 January 1987 and 31 December 2014 and compared them with controls matched on age and sex from the Total Population Register. We included 702 485 patients with HF and 1 306 183 controls. In patients with HF aged 18-64 years, short-term (29 days to 6 months) and long-term mortality (>11 years) decreased from 166 and 76.6 per 1000 person-years in 1987 to 2000 to 99.6 and 49.4 per 1000 person-years, respectively, in 2001 to 2014. During the same period, mortality improved marginally, in those aged ≥65 years: short-time mortality from 368.8 to 326.2 per 1000 person-years and long-term mortality from 219.6 to 193.9 per 1000 person-years. In 1987-2000, patients aged <65 years had more than three times higher risk of dying at 29 days to 6 months, with an hazard ratio (HR) of 3.66 [95% confidence interval (CI) 3.46-3.87], compared with controls (P < 0.0001) but substantially higher in 2001-2014 with an HR of 11.3 (95% CI 9.99-12.7, P < 0.0001). HRs for long-term mortality (6-10 and >11 years) increased moderately from 2.49 (95% CI 2.41-2.57) and 3.16 (95% CI 3.07-3.24) in 1987-2000 to 4.35 (95% CI 4.09-4.63) and 4.11 (95% CI 3.49-4.85) in 2001-2014, largely because survival among controls improved more than that among patients with HF (P < 0.0001).

CONCLUSIONS

Absolute survival improved in HF patients aged <65 years, but only marginally so in those aged ≥65 years. Compared with controls, both short-term and long-term relative risk of dying increased, especially in younger patients with HF.

Relative Validity of a Short 15-Item Food Frequency Questionnaire Measuring Dietary Quality, by the Diet History Method

Food frequency questionnaires (FFQ) are commonly used dietary assessment tools. The aim was to assess the relative validity of a 15-item FFQ, designed for the screening of poor dietary patterns with a validated diet history (DH). The study population was derived from the Gothenburg H70 Birth Cohort Studies. The DH registrations were harmonized in accordance with the FFQ frequencies. The agreement was assessed by Cohen's kappa with corresponding confidence intervals (CI) for the frequency and categorical variables. Bland-Altman plots were used for the numeric variables. The study comprised data from 848 individuals (55.2% women). Overall, there was high agreement between the methods, with the exact and adjacent level of agreement over 80% for eight variables. The proportion attributed to the opposite frequency was fairly low for most of the frequency variables. Most of the kappa values were in fair or moderate agreement. The highest kappa values were calculated for the type of cooking fat (k = 0.68, CI = 0.63-0.72) and sandwich spread (k = 0.55, CI = 0.49-0.53), and the lowest for type of bread (0.13, CI = 0.07-0.20) and sweets (0.22 CI = 0.18-0.27). In conclusion, the FFQ showed overall good agreement compared with the DH. We, therefore, think it, with some improvements, could serve as a simple screening tool for poor dietary patterns.

Opioid consumption in patients undergoing Roux-en-Y bariatric surgery compared with population controls with and without obesity

BACKGROUND

Patients with obesity are prescribed more opioids than the general population.

OBJECTIVES

To compare opioid consumption in patients with obesity who underwent Roux-en-Y bariatric surgery (RYGB) with population controls with and without obesity, not undergoing bariatric surgery, and to identify characteristics associated with opioid use.

SETTING

This study included all patients with a principal diagnosis of obesity, aged 18-72 years, with a RYGB surgical code in the Swedish Patient Register between 2007 and 2013.

METHODS

RYGB patients (n = 23,898) were age- and sex-matched with 1 control patient with obesity (n = 23,898) and 2 population controls without obesity (n = 46,064). Participants were classified as nonconsumers and consumers based on their opioid dispensations during the 12 months before baseline. Opioid consumption was assessed for 24 months.

RESULTS

Nonconsumers. Within 24 months, a significantly higher proportion of RYGB patients (16.6%) started using opioids compared with the controls with obesity (14.3%, P < .0001) and population controls (5.4%, P < .0001). RYGB patients and controls with obesity had higher median daily intake of opioid morphine equivalent (MEQ) (2.8 mg/d) than population controls (2.5 mg/d, P < .0001). Consumers. Within 24 months, the proportion of RYGB patients and controls with obesity that was using opioids were similar (53.1% and 53.4%), but higher compared to population controls (38.0%, P < .0001). The median daily opioid MEQ was higher among RYGB patients than in population controls (10.5 versus 7.8 mg/d, P < .0001). RYGB patients, overall, had higher incidence of bowel surgery and cholecystectomy compared with controls with obesity and population controls, leading to prolonged opioid use in this group. Opioid consumption in general was associated with chronic pain and psychiatric disorder, which were more common in patients with obesity than in the population controls.

CONCLUSION

RYGB surgery increased the risk of prolonged opioid use in patients with obesity who were nonconsumers before surgery but had no effect on overall opioid use among prior consumers. RYGB-associated complications requiring surgery influenced opioid use for both nonconsumers and consumers. Regular reassessments of pain mechanisms and specific treatment owing to type of pain could prevent unnecessary opioid use in this patient group.

Obesity, overweight and risk for cardiovascular disease and mortality in young women

AIMS

The aim of this study was to investigate the relation between body mass index (BMI) in young women, using weight early in pregnancy as a proxy for pre-pregnancy weight, and risk for early cardiovascular disease (CVD) and mortality.

METHODS AND RESULTS

In this prospective, registry-based study, we used weight data in early pregnancy from women, registered in the Swedish Medical Birth Registry, and who gave birth between 1982 and 2014 (n = 1,495,499; median age 28.3 years). Of the women, 118,212 (7.9%) were obese (BMI ≥ 30 kg/m²) and 29,630 (2.0%) severely obese (BMI ≥ 35 kg/m²). After a follow-up of median 16.3 years, we identified 3295 and 4375 cases of acute myocardial infarction (AMI) and ischemic stroke (IS) corresponding to 13.4 and 17.8 per 100,000 observation years, respectively, occurring at mean ages of 49.8 and 47.3 years. Compared to women with a BMI 20-<22.5 kg/m², the hazard ratio (HR) of AMI increased with higher BMI from 1.40 (95% confidence interval (CI) 1.27-1.54) among women with BMI 22.5-<25.0 kg/m² to 4.71 (95% CI 3.88-5.72) among women with severe obesity, with similar findings for IS and CVD death, after adjustment for age, pregnancy year, parity and comorbidities at baseline. Women with BMI 30-<35.0 and ≥35 kg/m² had increased all-cause mortality with adjusted HR 1.53 (95% CI 1.43-1.63) and 1.83 (95% CI 1.63-2.05), respectively.

CONCLUSION

A significant increase in the risk for early AMI, IS and CVD death was noticeable in overweight young women, with a marked increase in obese women.

Body Mass Index in Young Women and Risk of Cardiomyopathy: A Long-Term Follow-Up Study in Sweden

Supplemental Digital Content is available in the text.

Incidence rates of cardiomyopathies, which are a common cause of heart failure in young people, have increased during the last decades. An association between body weight in adolescence and future cardiomyopathy among men was recently identified. Whether or not this holds true also for women is unknown. The aim was therefore to determine whether for young women being overweight or obese is associated with a higher risk of developing cardiomyopathy.