Weight loss and mortality: a gender-specific analysis of the Tromsø study

Excess weight, weight gain, and prostate cancer risk and prognosis: the PROCA-life study

BACKGROUND

Studies of excess weight and weight changes throughout adult life for prostate cancer (PCa) risk and prognosis have shown inconsistent results.

METHODS

In a population-based cohort, the Prostate Cancer Study throughout life (PROCA-life), 16,960 healthy men from the prospective cohort Tromsø Study (1994-2016) were included. Body mass index (BMI) and weight were measured at all four attendings, and weight change was calculated as the difference between the first and last of either Tromsø4, Tromsø5 or Tromsø6. Overall, 904 men developed PCa during 16 years of follow-up, and Poisson regression with fractional polynomials was used to investigate trends in incidence. Cox proportional hazard and logistic regression models were used to study associations between measurements of BMI and weight change and PCa risk, severity, and mortality.

RESULTS

At study entry, 46% of the participants (median age 44 years) were overweight, and 14% were obese (BMI > 30 kg/m2). We observed a 127% increase in overall age adjusted PCa incidence in the cohort during 1995 through 2019. No overall associations between BMI or weight change and PCa risk were observed. However, in sub-group analysis, weight gain among obese men was associated with a three-fold higher PCa risk (HR 3.03, 95% CI 1.39-6.58) compared with obese men with stable weight. Overweight was associated with lower risk of metastatic cancer (OR 0.48, 95% CI 0.30-0.75) at diagnosis. Men with obesity had higher risk of PCa-specific death (HR 1.72, 95% CI 1.03-2.88), while nonsmoking obese PCa cases had two times higher PCa-specific mortality compared with normal weighted PCa cases (HR 2.10, 95% CI 1.11-3.70).

INTERPRETATION

In our cohort, weight gain among obese men was associated with higher risk of PCa, and obesity was associated with higher PCa-specific mortality, especially among nonsmokers. The relationship between weight and risk for PCa remains complicated, and future studies are needed to determine clinical implications.

Gender differences in midlife to later-life cumulative burden and variability of obesity measures and risk of all-cause and cause-specific mortality

BACKGROUND/OBJECTIVES

Previous studies have reported the gender-specific association between general and central obesity measures, using snapshot assessments, and mortality events. This study seeks to further explore this link by examining how the longitudinal cumulative burden and variability of obesity measures from midlife to later-life impact mortality events in the Atherosclerosis Risk in Communities (ARIC) study population, specifically in relation to gender differences.

SUBJECTS/METHODS

Using data from the ARIC study, a total of 7615 (4360 women) participants free of cardiovascular disease, cancer, and early mortality events were included in the data analysis. Longitudinal cumulative burden (estimated by the area under the curve (AUC) using a quadratic mixed-effects method) and variability (calculated according to average successive variability (ASV)) were considered as exposures, separately and all together. Cox proportional hazard regression models were used to estimate multivariable-adjusted standardized hazard ratios.

RESULTS

The mean age was 62.4 and the median follow-up was 16.9 years. In men, AUCs of waist-related obesity measures, and also ASVs of all obesity measures were associated with increased all-cause mortality risk. In women, waist circumference and waist-to-height ratio AUCs were associated with increased all-cause mortality risk. Regarding cardiovascular mortality, all adiposity measures ASVs in both genders and waist-related obesity measures AUCs in men were associated with increased risk. Significant gender differences were found for the associations between cumulative and variability of waist-to-hip ratio for all-cause mortality and all adiposity measures ASVs for cardiovascular mortality risk with higher impact among men.

CONCLUSIONS

Cumulative burden and variability in general and central obesity measures were associated with higher all-cause and cardiovascular mortalities among men. In women, general obesity measures variability, as well as cumulative and variability of central adiposity measure, increased all-cause mortality risk.

Vertebral Fractures Assessed by Dual-Energy X-Ray Absorptiometry and All-Cause Mortality: The Tromsø Study, 2007-2020

Vertebral fractures have been associated with increased mortality, but findings are inconclusive, and many vertebral fractures avoid clinical attention. We investigated this association in a general population of 2,476 older adults aged ≥55 years from Tromsø, Norway, who were followed over 2007-2020, using dual-energy x-ray absorptiometry (DXA) at baseline to evaluate vertebral fractures (mild, moderate, or severe). We used multiple Cox regression models to estimate hazard ratios (HRs) for all-cause mortality, adjusted for age, sex, body mass index, education, smoking, alcohol intake, cardiovascular disease, and respiratory disease. Mean follow-up in the cohort was 11.2 (standard deviation, 2.7) years; 341 participants (13.8%) had ≥1 vertebral fracture at baseline, and 636 participants (25.7%) died between baseline and follow-up. Full-adjustment models showed a nonsignificant association between vertebral fracture status (yes/no) and mortality. Participants with ≥3 vertebral fractures (HR = 2.43, 95% confidence interval: 1.57, 3.78) or ≥1 severe vertebral fracture (HR = 1.65, 95% confidence interval: 1.26, 2.15) had increased mortality compared with those with no vertebral fractures. Dual-energy x-ray absorptiometry-based screening could be a potent and feasible tool in detecting vertebral fractures that are often clinically silent yet independently associated with premature death. Our data indicated that detailed vertebral assessment could be warranted for a more accurate survival estimation.

Observational Evidence for Unintentional Weight Loss in All-Cause Mortality and Major Cardiovascular Events: A Systematic Review and Meta-Analysis

The obesity paradox has been described in several observational cohorts and meta-analysis. However, evidence of the intentionality of weight loss in all-cause deaths and major cardiovascular events (MACE) in prospective cohorts is unclear. We analysed whether involuntary weight loss is associated with increased cardiovascular events and mortality. In a systematic review, we searched multiple electronic databases for observational studies published up to October 2016. Studies reporting risk estimates for unintentional weight loss compared with stable weight in MACE and mortality were included. Fifteen studies met the selection criteria, with a total of 178,644 participants. For unintentional weight loss, we found adjusted risk ratios (RRs) with confidence intervals (CIs) of 1.38 (95% CI: 1.23, 1.53) and 1.17 (95% CI: 0.98, 1.37) for all-cause mortality and MACE, respectively. Participants with comorbidities, overweight and obese populations, and older adults yielded RRs (95% CI) of 1.49 (1.30, 1.68), 1.11 (1.04, 1.18), and 1.81 (1.59, 2.03), respectively. Unintentional weight loss had a significant impact on all-cause mortality. We found no protective effect of being overweight or obese for unintentional weight loss and MACE.

Change in body size and mortality: a systematic review and meta-analysis

Background

: Observational studies have reported that weight loss in later life is associated with an increased risk of mortality. However, the association with weight gain is unclear. We conducted a systematic review and meta-analysis of prospective studies assessing the association of weight gain and loss, and mortality.

Methods

: We searched PubMed, Scopus and Web of Science for articles published before 5 September 2015. We included prospective studies that reported enough information to extract hazard ratios (HRs) with the corresponding 95% confidence intervals (CIs) for the association between weight gain and/or weight loss, and all-cause and cause-specific mortality. The estimates were pooled using a random-effects model. Meta-regression models were fitted to explore sources of potential between-study heterogeneity.

Results

: A total of 25 (providing data from 437 772 participants with 34 038 deaths from all causes) and 24 studies (434 694 participants with 31 978 deaths) presented results for the exposures, weight loss and weight gain. Weight loss compared with a stable weight was associated with an increased risk of all-cause (pooled HR: 1.45; 95% CI: 1.34, 1.58), and cardiovascular disease (CVD) mortality (1.50; 1.32, 1.70) and a slightly increased risk of cancer mortality (1.19; 0.97, 1.46). Weight gain was associated with an increased risk of CVD mortality (1.21; 1.07, 1.36) and a slightly increased risk of all-cause mortality (1.07; 1.01, 1.13) and cancer mortality (1.04; 0.96, 1.13). Considerable heterogeneity was observed; the method used to ascertain body size and the proportion of the baseline sample included in the final analysis explained most of the heterogeneity.

Conclusion

: Weight loss and weight gain in midlife are associated with increased risk of all-cause and CVD mortality.

What is the impact of underweight on self-reported health trajectories and mortality rates: a cohort study

Background

Utilizing a cohort study design combining a survey approach with repeated physical examinations, we examined the independent effects of BMI on mortality and self-reported health (SRH) and whether these independent effects change as people grow older.

Methods

The Tromsø Study consists of six surveys conducted in the municipality of Tromsø, Norway, with large representative samples of a general population. In total, 31,985 subjects participated in at least one of the four surveys administered between 1986 and 2008. Outcomes of interest were SRH and all-cause mortality.

Results

Overweight and underweight subjects reported significantly lower levels of SRH, but age affected the thinnest subjects more than all others. The SRH trajectory of underweight subjects at age 25 was slightly above the other categories (0.08), but it fell to −.30 below the reference category at age 90. For obese subjects, the difference was −0.15 below the reference category at age 25 and −0.18 below at age 90. This implies that even though a low BMI was slightly beneficial at a young age, it represented an increasing risk with age that crossed the reference curve at age 38 and even crossed the obese trajectory at age 67 in the full fitted model. The proportional hazard ratio for those who were underweight was 1.69 (95% CI: 1.38-2.06) for all-cause death as compared to 1.12 (95% CI: 1.02-1.23) for obese subjects.

Conclusion

BMI affected SRH and all-cause mortality independently from comorbidity, mental health, health-related behaviors and other biological risk factors. Being underweight was associated with excess mortality as compared to all others, and age affected the thinnest subjects more than all others. Weight increase was beneficial for mortality but not for SRH among the underweight. The rapid decline of SRH with increasing age suggests that particular attention should be paid to underweight after 38 years of age.

Electronic supplementary material

The online version of this article (10.1186/s12955-017-0766-x) contains supplementary material, which is available to authorized users.

Body mass index and all-cause mortality among type 2 diabetes mellitus patients: Findings from the 5-year follow-up of the MADIABETES cohort

PURPOSE

To analyse the association between body mass index (BMI) and all-cause mortality in a 5-year follow-up study with Spanish type 2 diabetes mellitus (T2DM) patients, seeking gender differences.

METHODS

3443 T2DM outpatients were studied. At baseline and annually, patients were subjected to anamnesis, a physical examination, and biochemical tests. Data about demographic and clinical characteristics was also recorded, as was the treatment each patient had been prescribed. Mortality records were obtained from the Spanish National Institute of Statistics. Survival curves for BMI categories (Gehan-Wilcoxon test) and a multivariate Cox proportional hazard analysis were performed to identify adjusted Hazard Ratios (HRs) of mortality.

RESULTS

Mortality rate was 26.38 cases per 1000patient-years (95% CI, 23.92-29.01), with higher rates in men (28.43 per 1000patient-years; 95% CI, 24.87-32.36) than in women (24.31 per 1000patient-years; 95% CI, 21.02-27.98) (p=0.079). Mortality rates according to BMI categories were: 56.7 (95% CI, 40.8-76.6), 28.4 (95% CI, 22.9-34.9), 24.8 (95% CI, 21.5-28.5), 21 (95% CI, 16.3-26.6) and 23.7 (95% CI, 14.3-37) per 1000person-years for participants with a BMI of <23, 23-26.8, 26.9-33.1, 33.2-39.4, and >39.4kg/m², respectively. The BMI values associated with the highest all-cause mortality were <23kg/m², but only in males [HR: 2.78 (95% CI, 1.72-4.49; p<0.001)], since in females this association was not significant [HR: 1.14 (95% CI, 0.64-2.04; p=0.666)] (reference category for BMI: 23.0-26.8kg/m²). Higher BMIs were not associated with higher mortality rates.

CONCLUSIONS

In an outpatient T2DM Mediterranean population sample, low BMI predicted all-cause mortality only in males.

Psychometric properties of a MOVE!23 subscale: Perceived Contributors to Weight Change in a national sample of veterans

The MOVE!23, a questionnaire to assess weight-related domains in veterans, was examined. Factor analysis of Perceived Contributors to Weight Change revealed three factors (psychosocial, eating behavior, and medical) that were positively correlated with body mass index, and psychiatric and medical comorbidity (p's < 0.001). Multivariable cumulative logit models modeling the factor scores indicated that women were more likely than men to endorse psychosocial (odds ratio = 2.15, confidence interval = 2.04-2.27) and medical (odds ratio = 1.69, confidence interval = 1.59-1.79) items. The MOVE!23 Perceived Contributors to Weight Change subscale is a reliable and valid measure that is associated with body mass index and may assist in tailoring treatments according to gender and comorbidity.

Weight loss and premature death: the 1946 British birth cohort study

Objective

The relationship between weight loss and mortality has important clinical and public health significance but has proved to be complex. Evidence is mixed and particularly limited on the association between weight loss in mid-life and premature death (i.e. before 65 years of age), a small albeit important segment of total mortality. We aimed to study the association between midlife weight change and mortality accounting for health and lifestyle characteristics, and also considering potential bias due to preexisting chronic diseases and smoking status.

Design

Longitudinal, population-based, ‘the 1946 British’ birth cohort study.

Subjects and Measures

In 2750 men and women, mortality from age 53 through 65 years was analyzed according to categories of measured 10 year weight change between 43 and 53 years. Cox's hazard ratios (HR) were progressively adjusted for socio-demographic, lifestyle and health characteristics.

Results

Nearly 20% of participants lost weight and over 50% gained 5 kg or more in midlife. There were 164 deaths. Compared to those who gained between 2 and 5 kg, those who lost 5 kg or more had an increased risk of premature death independently of midlife physical activity, socio-economic circumstances and educational attainment. This association was unaltered when highest weight loss (lost more than 15 Kg) (p = 0.04) and early deaths were excluded (p<0.001), but was no longer significant after adjustment for cardiovascular risk factors and health status (HR = 1.8; 95% CI: 0.9 to 3.5).

Conclusion

The inverse association between weight loss in midlife and higher risk of premature death may be explained by vascular risk factors and ill health. In consideration of the burden of premature death, closer monitoring of weight loss in mid-life is warranted.

Cross-sectional associations between prevalent vertebral fracture and pulmonary function in the sixth Tromsø study

Background

Persons with vertebral fracture may have reduced pulmonary function, but this association has not been much studied. The aim of this cross-sectional study was therefore to examine the relationship between vertebral fracture and pulmonary function in a general, elderly population.

Methods

Vertebral morphometry was used for vertebral fracture assessment in 2132 elderly men (n = 892) and women (n = 1240) aged 55 to 87 years in the population-based Tromsø Study 2007–08. Pulmonary function was examined by spirometry. Pulmonary function was expressed as FVC% predicted, FEV₁% predicted, and FEV₁/FVC% predicted values, adjusted FVC, FEV₁, and FEV₁/FVC, and obstructive and restrictive ventilatory impairment. Vertebral fracture was classified according to appearance, number, severity, and location of fractures. Associations were analyzed using general linear and logistic models.

Results

FVC% predicted and FEV₁% predicted values were not associated with vertebral fracture (P > 0.05), whereas FEV₁/FVC% predicted ratio was associated with both prevalent fracture, number of fractures, severity of fractures, and fracture site in men (P < 0.05), but not in women. When FVC, FEV₁, and FEV₁/FVC values were adjusted for multiple covariates, we found no significant association with vertebral fracture. Obstructive and restrictive ventilatory impairment was not associated with prevalent vertebral fracture.

Conclusions

In conclusion, this study did not confirm any clinically relevant associations between prevalent vertebral fracture and ventilatory impairment in elderly individuals.

Body mass index, gender, and clinical outcome among hypertensive and diabetic patients with stage A/B heart failure

OBJECTIVE

The existence of an "obesity paradox" in asymptomatic patients with preclinical heart failure (HF) has not been investigated. The prognostic value of BMI in a cohort of hypertensive and diabetic patients with stage A/B HF enrolled in the PROBE-HF study was explored.

DESIGN AND METHODS

BMI was measured in 1003 asymptomatic subjects (age 66.4 ± 7.8 years, 48% males) with hypertension and/or type 2 diabetes and no clinical evidence of HF. Predefined endpoints were all-cause mortality and a composite of death and hospitalization for cardiac causes.

RESULTS

During a follow-up of 38.5 ± 4.1 months, 33 deaths were observed. Mortality in the normal BMI group (1.6 deaths per 100 patient-years) did not differ to that in the overweight group (1.1 per 100 patient-years, p = 0.31), but was higher than that in the obese group (0.4 per 100 patient-years, p = 0.0089). In multivariable analysis, obesity (hazard ratio [HR] 0.27 [0.09-0.85], p = 0.025) but not overweight (HR 0.68 [0.32-1.45], p = 0.32) was associated with lower risk of death. Obesity was also independently associated with reduced risk of the composite endpoint (HR 0.54 [0.28-0.99], p = 0.047).

CONCLUSION

In asymptomatic hypertensive and diabetic patients with preclinical HF, obesity is associated with better survival and reduced risk of events.

Modeling obesity histories in cohort analyses of health and mortality

There is great interest in understanding the role of weight dynamics over the life cycle in predicting the incidence of disease and death. Beginning with a Medline search, we identify, classify, and evaluate the major approaches that have been used to study these dynamics. We identify four types of models: additive models, duration-of-obesity models, additive-weight-change models, and interactive models. We develop a framework that integrates the major approaches and shows that they are often nested in one another, a property that facilitates statistical comparisons. Our criteria for evaluating models are two-fold: the model's interpretability and its ability to account for observed variation in health outcomes. We apply two sets of nested models to data on adults age 50-74 years at baseline in two national probability samples drawn from National Health and Nutrition Examination Survey. One set of models treats obesity as a dichotomous variable and the other treats it as a continuous variable. In three of four applications, a fully interactive model does not add significant explanatory power to the simple additive model. In all four applications, little explanatory power is lost by simplifying the additive model to a duration model in which the coefficients of weight at different ages are set equal to one another. Other versions of a duration-of-obesity model also perform well, underscoring the importance of obesity at early adult ages for mortality at older ages.