Invitation to a population-based cohort study: differences between subjects recruited using various strategies

Birth weight and birth length affect future fracture risk differently in men and women

We wanted to determine if there are any associations between birth factors and adult fracture risk. For women only, shorter birth length was associated with lower relative fracture risk. For women and men, individuals who were long at birth as well as tall in adulthood had a substantially higher relative fracture risk.

PURPOSE

We aimed to examine associations between birth anthropometry and adult fracture risk and to investigate if developmental mismatch is associated with fracture risk.

METHODS

We included 4635 participants (476 women and 4159 men; born 1921-1950) with hospital and national registry-based data on birth anthropometry and adult fractures (≥ 50 years). We tested associations by Cox proportional hazards regressions and present hazard ratios (HR) with 95% confidence intervals.

RESULTS

In total, 1215 (26%) suffered ≥ 1 fracture during a mean observation period of 26 years. In women, unadjusted analyses indicated that both higher birth weight (HR 1.42 per kg (1.10-1.84)) and birth length (1.10 per cm (1.05-1.17)) were associated to higher adult fracture risk. After adjustment (year of birth and gestational age), statistical significance remained only for birth length, HR 1.10 per cm (1.04-1.17). For men, no associations were apparent. We found no associations between developmental mismatch (lower birth weight followed by higher adult weight) and adult fracture risk. However, for both sexes, being born tall and staying tall into adulthood was associated with a markedly higher (55-105%) relative fracture risk (HR women 2.09 (1.18-3.68), men 1.55 (1.19-2.03)) compared to being born short and remaining short in adulthood.

CONCLUSION

In this study, being born shorter and lighter was associated with a lower risk for fractures ≥ 50 years in women. However, analyses indicated that tall adults who were also long at birth may be at markedly higher risk of fractures; this warrants further examinations.

A systematic evaluation of seven different scores representing the EAT-Lancet reference diet and mortality, stroke, and greenhouse gas emissions in three cohorts

Different approaches have been used for translation of the EAT-Lancet reference diet into dietary scores that can be used to assess health and environmental impact. Our aim was to compare the different EAT-Lancet diet scores, and to estimate their associations with all-cause mortality, stroke incidence, and greenhouse gas emissions. We did a systematic review (PROSPERO, CRD42021286597) to identify different scores representing adherence to the EAT-Lancet reference diet. We then qualitatively compared the diet adherence scores, including their ability to group individuals according the EAT-Lancet reference diet recommendations, and quantitatively assessed the associations of the diet scores with health and environmental outcome data in three diverse cohorts: the Danish Diet, Cancer and Health Cohort (DCH; n=52 452), the Swedish Malmö Diet and Cancer Cohort (MDC; n=20 973), and the Mexican Teachers' Cohort (MTC; n=30 151). The DCH and MTC used food frequency questionnaires and the MDC used a modified diet history method to assess dietary intake, which we used to compute EAT-Lancet diet scores and evaluate the associations of scores with hazard of all-cause mortality and stroke. In the MDC, dietary greenhouse gas emission values were summarised for every participant, which we used to predict greenhouse gas emissions associated with varying diet adherence scores on each scoring system. In our review, seven diet scores were identified (Knuppel et al, 2019; Trijsburg et al, 2020; Cacau et al, 2021; Hanley-Cook et al, 2021; Kesse-Guyot et al, 2021; Stubbendorff et al, 2022; and Colizzi et al, 2023). Two of the seven scores (Stubbendorff and Colizzi) were among the most consistent in grouping participants according to the EAT-Lancet reference diet recommendations across cohorts, and higher scores (greater diet adherence) were associated with decreased risk of mortality (in the DCH and MDC), decreased risk of incident stroke (in the DCH and MDC for the Stubbendorff score; and in the DCH for the Colizzi score), and decreased predicted greenhouse gas emissions in the MDC. We conclude that the seven different scores representing the EAT-Lancet reference diet had differences in construction, interpretation, and relation to disease and climate-related outcomes. Two scores generally performed well in our evaluation. Future studies should carefully consider which diet score to use and preferably use multiple scores to assess the robustness of estimations, given that public health and environmental policy rely on these estimates.

Mammographic features at primary breast cancer diagnosis in relation to recurrence-free survival

PURPOSE

The number of women living with breast cancer (BC) is increasing, and the efficacy of surveillance programs after BC treatment is essential. Identification of links between mammographic features and recurrence could help design follow up strategies, which may lead to earlier detection of recurrence. The aim of this study was to analyze associations between mammographic features at diagnosis and their potential association with recurrence-free survival (RFS).

METHODS

Women with invasive BC in the prospective Malmö Diet and Cancer Study (n = 1116, 1991-2014) were assessed for locoregional and distant recurrences, with a median follow-up of 10.15 years. Of these, 34 women were excluded due to metastatic disease at diagnosis or missing recurrence data. Mammographic features (breast density [BI-RADS and clinical routine], tumor appearance, mode of detection) and tumor characteristics (tumor size, axillary lymph node involvement, histological grade) at diagnosis were registered. Associations were analyzed using Cox regression, yielding hazard ratios (HR) with 95 % confidence intervals (CI).

RESULTS

Of the 1082 women, 265 (24.4 %) had recurrent disease. There was an association between high mammographic breast density at diagnosis and impaired RFS (adjusted HR 1.32 (0.98-1.79). In analyses limited to screen-detected BC, this association was stronger (adjusted HR 2.12 (1.35-3.32). There was no association between mammographic tumor appearance and recurrence.

CONCLUSION

RFS was impaired in women with high breast density compared to those with low density, especially among women with screen-detected BC. This study may lead to insights on mammographic features preceding BC recurrence, which could be used to tailor follow up strategies.

High consumption of dairy products and risk of major adverse coronary events and stroke in a Swedish population

The association between the consumption of dairy products and risk of CVD has been inconsistent. There is a lack of studies in populations with high intakes of dairy products. We aimed to examine the association between intake of dairy products and risk of incident major adverse coronary events and stroke in the Swedish Malmö Diet and Cancer cohort study. We included 26 190 participants without prevalent CVD or diabetes. Dietary habits were obtained from a modified diet history, and endpoint data were extracted from registers. Over an average of 19 years of follow-up, 3633 major adverse coronary events cases and 2643 stroke cases were reported. After adjusting for potential confounders, very high intakes of non-fermented milk (>1000 g/d) compared with low intakes (<200 g/d) were associated with 35 % (95 % CI (8, 69)) higher risk of major adverse coronary events. In contrast, moderate intakes of fermented milk (100-300 g/d) were associated with a lower risk of major adverse coronary events compared with no consumption. Intakes of cheese (only in women) and butter were inversely associated with the risk of major adverse coronary events. We observed no clear associations between any of the dairy products and stroke risk. These results highlight the importance of studying different dairy foods separately. Further studies in populations with high dairy consumption are warranted.

NADPH Oxidase 3: Beyond the Inner Ear

Reactive oxygen species (ROS) were formerly known as mere byproducts of metabolism with damaging effects on cellular structures. The discovery and description of NADPH oxidases (Nox) as a whole enzyme family that only produce this harmful group of molecules was surprising. After intensive research, seven Nox isoforms were discovered, described and extensively studied. Among them, the NADPH oxidase 3 is the perhaps most underrated Nox isoform, since it was firstly discovered in the inner ear. This stigma of Nox3 as "being only expressed in the inner ear" was also used by me several times. Therefore, the question arose whether this sentence is still valid or even usable. To this end, this review solely focuses on Nox3 and summarizes its discovery, the structural components, the activating and regulating factors, the expression in cells, tissues and organs, as well as the beneficial and detrimental effects of Nox3-mediated ROS production on body functions. Furthermore, the involvement of Nox3-derived ROS in diseases progression and, accordingly, as a potential target for disease treatment, will be discussed.

Oxidative stress-related genetic variation and antioxidant vitamin intake in intact and ruptured abdominal aortic aneurysm: a Swedish population-based retrospective cohort study

AIMS

The aim of this study is to investigate how genetic variations in genes related to oxidative stress, intake of antioxidant vitamins, and any potential interactions between these factors affect the incidence of intact abdominal aortic aneurysm (AAA) and its rupture (rAAA), accounting for sex differences where possible.

METHODS AND RESULTS

The present retrospective cohort study (n = 25 252) uses baseline single-nucleotide polymorphisms (SNPs) and total antioxidant vitamin intake data from the large population-based, Malmö Diet and Cancer Study. Cumulative incidence of intact AAA was 1.6% and of rAAA 0.3% after a median follow-up of 24.3 years. A variant in NOX3 (rs3749930) was associated with higher rAAA risk in males [adjusted hazard ratio (aHR): 2.49; 95% confidence interval (CI): 1.36-4.35] and the overall population (aHR: 1.88; 95% CI: 1.05-3.37). Higher intakes of antioxidant vitamins, riboflavin, and folate were associated with 20% and 19% reduced intact AAA incidence, respectively. Interestingly, the inverse associations between riboflavin and vitamin D intake with intact AAA incidence were stronger in the individuals carrying the NOX3 variant as compared with the wild-type recessive genotype, i.e. by 60% and 66%, respectively (P for interaction < 0.05). Higher riboflavin intake was associated with a 33% male-specific intact AAA risk reduction, while higher intake of vitamin B12 intake was associated with 55% female-specific intact AAA risk increase; both these associations were significantly modified by sex (P for interaction < 0.05).

CONCLUSIONS

Our findings highlight the role of oxidative stress genetic variations and antioxidant vitamin intake in AAA. Although a low AAA/rAAA sample size limited some analyses, especially in females, our findings highlight the need for future randomized controlled trials and mechanistic studies, to explore the potential benefits of antioxidant vitamins while accounting for genetic and sex differences.

Red cell distribution width and its polygenic score in relation to mortality and cardiometabolic outcomes

Introduction

Elevated red cell distribution width (RDW) has been associated with a range of health outcomes. This study aims to examine prognostic and etiological roles of RDW levels, both phenotypic and genetic predisposition, in predicting cardiovascular outcomes, diabetes, chronic kidney disease (CKD) and mortality.

Methods

We studied 27,141 middle-aged adults from the Malmö Diet and Cancer study (MDCS) with a mean follow up of 21 years. RDW was measured with a hematology analyzer on whole blood samples. Polygenic scores for RDW (PGS-RDW) were constructed for each participant using genetic data in MDCS and published summary statistics from genome-wide association study of RDW (n = 408,112). Cox proportional hazards regression was used to assess associations between RDW, PGS-RDW and cardiovascular outcomes, diabetes, CKD and mortality, respectively.

Results

PGS-RDW was significantly associated with RDW (Pearson's correlation coefficient = 0.133, p < 0.001). RDW was significantly associated with incidence of stroke (hazard ratio (HR) per 1 standard deviation = 1.06, 95% confidence interval (CI): 1.02-1.10, p = 0.003), atrial fibrillation (HR = 1.09, 95% CI: 1.06-1.12, p < 0.001), heart failure (HR = 1.13, 95% CI: 1.08-1.19, p < 0.001), venous thromboembolism (HR = 1.21, 95% CI: 1.15-1.28, p < 0.001), diabetes (HR = 0.87, 95% CI: 0.84-0.90, p < 0.001), CKD (HR = 1.08, 95% CI: 1.03-1.13, p = 0.004) and all-cause mortality (HR = 1.18, 95% CI: 1.16-1.20, p < 0.001). However, PGS-RDW was significantly associated with incidence of diabetes (HR = 0.96, 95% CI: 0.94-0.99, p = 0.01), but not with any other tested outcomes.

Discussion

RDW is associated with mortality and incidence of cardiovascular diseases, but a significant association between genetically determined RDW and incident cardiovascular diseases were not observed. However, both RDW and PGS-RDW were inversely associated with incidence of diabetes, suggesting a putative causal relationship. The relationship with incidence of diabetes needs to be further studied.

Comparisons of Different Carbohydrate Quality Indices for Risk of Type 2 Diabetes in the Malmö Diet and Cancer Study

Carbohydrate quality might be more important than quantity to reduce type 2 diabetes (T2D) risk. Various metrics of carbohydrate quality exist; however, their associations with T2D have only been studied to a limited extent. Consequently, the aim was to investigate the association between four different pre-defined carbohydrate quality indices, with various amounts of fiber (≥1 g) and free sugar (<1 or <2 g) per 10 g of carbohydrates, and T2D risk among 26,622 individuals without diabetes from the Malmö Diet and Cancer cohort. Dietary data were collected through a food diary, diet frequency questionnaire, and interview. After a mean follow-up of 18 years, 4046 cases were identified through registers. After adjusting for potential confounders, no statistically significant associations were found for any of the indices. When excluding individuals with past dietary changes and potential misreporting of energy (36% of the population), lower risk was found for the following intake ratios: 10:1:2 carbohydrate:fiber:free sugar (HR = 0.82; 95% CI = 0.70-0.97), and 10:1&1:2 carbohydrate:fiber and fiber:free sugar, respectively (HR = 0.84; 95% CI = 0.72-0.97). Our findings indicate that adherence to a diet with high amounts of fiber and moderate amounts of free sugar in relation to total carbohydrate intake may be associated with a lower risk of T2D.

Investigating the prognostic value of mammographic breast density and mammographic tumor appearance in women with invasive breast cancer: The Malmö Diet and cancer study

BACKGROUND

High breast density is a risk factor for breast cancer. However, whether density is a prognostic factor is debatable. Also, tumor appearances are related to tumor characteristics. Here we investigate the relationship between breast cancer-specific survival and mammographic breast density and mammographic tumor appearances.

METHODS

Women in the Malmö Diet and Cancer study with invasive breast cancer 1991-2014 were included (n = 1116). Mammographic information, patient and tumor characteristics, vital status, and causes of death were collected through 2018. Breast cancer-specific survival was assessed with Kaplan-Meier estimates and Cox proportional hazard models. Analyses were adjusted for established prognostic factors and stratified by detection mode.

RESULTS

High breast density did not significantly impact breast cancer-specific survival. However, there may be increased risk in women with dense breasts and screening-detected tumors (HR 1.45, CI 0.87-2.43). Neither did tumor appearance impact breast cancer-specific survival at long-term follow-up.

CONCLUSIONS

Breast cancer prognosis in women with high breast density on mammography does not seem impaired compared to women with less dense breasts, once the cancer is established. Neither does mammographic tumor appearance seem to inflict on prognosis, findings that can be of value in the management of breast cancer.

Imaging ovarian cancer - from baseline characteristics to high-risk image factors

BACKGROUND

Imaging ovarian cancer (OC) includes evaluating peritoneal carcinomatosis (PC) and enlarged cardio phrenic lymph nodes (CPLN) by computed tomography (CT), and thorough evaluation is tedious work. A "CT short score" with high-risk CT parameters might be a more pragmatic approach, but it is not known if such a short score associates with aggressive OC subtypes and impaired OC survival. Further, it is not known if certain established OC risk factors are linked to high-risk CT-findings which would be important in image evaluation. Herein, we investigate a CT short score and its relation to baseline characteristics, OC subtypes, and survival.

METHODS

The Malmö Diet and Cancer Study is a prospective cohort that included 17,035 women (1991-1996). Baseline characteristics and tumor information on 159 OC and information on OC specific survival (last follow-up, 2017-12-31) was registered. A CT short score (CPLN and PC-index (PCI) in seven regions) was registered and associations with clinical stage [stage I vs. advanced stage (II-IV), histological type/grade (high grade serous and endometrioid vs. other subtypes], and OC-specific survival were analyzed with logistic and Cox regression, respectively. Parity and menopausal status were analyzed in relation to short score and PCI.

RESULTS

There was an association between higher short score and advanced clinical stage (adjusted OR 2.76 (1.42-5.38)), adjusted for age at diagnosis and histological type/grade. Higher short score was associated with impaired OC specific survival (adjusted HR 1.17 (1.01-1.35)), adjusted for age at diagnosis, histological type/grade, and clinical stage. There were no significant associations between parity, menopausal status, and short score/PCI.

CONCLUSIONS

CT short score was significantly associated with advanced clinical stages and impaired OC survival. A pragmatic approach (based on CT) to evaluate high risk image findings in OC could help reduce radiologists' workload and at the same time provide structured reports to surgeons and oncologists involved in OC care.

Sex-Specific Risk Factors for Deep Venous Thrombosis and Pulmonary Embolism in a Population-Based Historical Cohort Study of Middle-Aged and Older Individuals

Background Whether sex-specific differences exist for risk factors for pulmonary embolism (PE) and deep venous thrombosis (DVT), with the exception of pregnancy and estrogen therapy, has been sparsely studied. We aimed to study whether sex-specific differences of risk factors exist for noncancer-related DVT and PE in middle-aged and older individuals without cardiovascular history or previous diagnosis in a population-based historical (retrospective) cohort. Methods and Results Potential venous thromboembolism (VTE) risk factors were registered at baseline in 15 807 women and 9996 men aged 44 to 74 years, who participated in the Malmö Diet and Cancer study (1991-1996). We excluded subjects with a previous history of VTE, cancer, a diagnosis of cardiovascular disease, or a diagnosis of cancer-associated VTE during follow-up. Patients were followed up from baseline until the first event of PE or DVT, death, or December 31, 2018. During the follow-up period, 365 (2.3%) women and 168 (1.7%) men were affected by first DVT, and 309 (2.0%) women and 154 (1.5%) men were affected by first PE. In the multivariable Cox regression models, the anthropometric obesity markers of weight, body mass index, waist and hip circumference, fat percentage, and muscle weight were in a dose-dependent way associated with DVT and PE among women but not men. In an analysis that included patients with cardiovascular disease and cancer-related VTE, the results were similar for women. For men, several obesity measures became significantly associated with PE or DVT but were weaker than in women, especially for DVT. Conclusions Anthropometric obesity measures are more important risk factors for both DVT and PE among women than men, especially for individuals without cardiovascular history or previous diagnosis or cancer-related VTE.

Early menopause and weight loss are significant factors associated with risk of future fracture in middle-aged women

BACKGROUND

To identify factors related to reproductive history and weight change associated with first incident fracture in middle-aged women.

METHODS

In total, 18,326 women from the Malmö Diet and Cancer study were included in this prospective population-based cohort study. Participants were included 1991-1996 and followed to 2016. Using data from the National Patient Registry, linked with every participants' unique personal identification number, any first fracture affecting spine, thoracic cage, upper and lower extremities was identified. The association of baseline factors with incident fracture risk was analyzed using Cox regression models.

RESULTS

For participating women, median age 56.0 years, the multivariable Cox regression analysis observed that early menopause (40-44 years) (hazard ratio (HR) 1.14, 95% confidence interval (CI) 1.03-1.27) but not premature menopause < 40 years (HR 1.06, 95% CI 0.91-1.24) was associated with future fracture risk. Self-reported weight loss since age 20 was also associated with future fracture risk (HR 1.39, 95% CI 1.17-1.65) whereas a daily alcohol consumption in the third quartile (5.36-11.42 g/day) compared to the lowest quartile (0-0.80 g/day) was associated with decreased future fracture risk (HR 0.88, 95% CI 0.81-0.96). The multivariable Cox regression analysis also observed that increasing age and weight at baseline, current smoking, a positive history of previous fracture and family history of fractures were associated with increased fracture risk whereas an increasing BMI was associated with a decreased fracture risk. No association to parity or period of lactation was observed nor ever-use of oral contraceptives and menopausal hormone therapy.

CONCLUSION

This study shows that early menopause between 40 to 45 years and self-reported weight loss since age of 20 are relevant factors associated with increased fracture risk in middle-aged women. These factors were independent of traditional predictors of fracture risk among women and may be considered in preventive initiatives.

TRIAL REGISTRATION

Clinicaltrials.gov with identifier: NCT04151732, since Nov 5th 2018.

Predicting Sensitivity to Adverse Lifestyle Risk Factors for Cardiometabolic Morbidity and Mortality

People appear to vary in their susceptibility to lifestyle risk factors for cardiometabolic disease; determining a priori who is most sensitive may help optimize the timing, design, and delivery of preventative interventions. We aimed to ascertain a person’s degree of resilience or sensitivity to adverse lifestyle exposures and determine whether these classifications help predict cardiometabolic disease later in life; we pooled data from two population-based Swedish prospective cohort studies (n = 53,507), and we contrasted an individual’s cardiometabolic biomarker profile with the profile predicted for them given their lifestyle exposure characteristics using a quantile random forest approach. People who were classed as ‘sensitive’ to hypertension- and dyslipidemia-related lifestyle exposures were at higher risk of developing cardiovascular disease (CVD, hazards ratio 1.6 (95% CI: 1.3, 1.91)), compared with the general population. No differences were observed for type 2 diabetes (T2D) risk. Here, we report a novel approach to identify individuals who are especially sensitive to adverse lifestyle exposures and who are at higher risk of subsequent cardiovascular events. Early preventive interventions may be needed in this subgroup.

Association of Blood Pressure with Prostate Cancer Risk by Disease Severity and Prostate Cancer Death: A Pooled Cohort Study

BACKGROUND

The association of blood pressure (BP) with prostate cancer risk after accounting for asymptomatic prostate-specific antigen (PSA) testing, and with prostate cancer death, is unclear.

METHODS

We investigated BP, measured at a mean age of 38 years among 430,472 men from five Swedish cohorts, in association with incident prostate cancer (n = 32,720) and prostate cancer death (n = 6718). HRs were calculated from multivariable Cox regression models.

RESULTS

Increasing systolic and diastolic BP levels combined were associated with a slightly lower prostate cancer risk, with a HR of 0.98 (95% CI, 0.97-0.99) per standard deviation (SD) of mid-BP (average of systolic and diastolic BP). The association was restricted to the PSA era (1997 onwards, HR, 0.96; 95% CI, 0.95-0.98), to diagnoses initiated by a PSA test in asymptomatic men (HR, 0.95; 95% CI, 0.93-0.97), and to low-risk prostate cancer (HR, 0.95; 95% CI, 0.92-0.97). There was no clear association with more advanced disease at diagnosis. In cases, a slightly higher risk of prostate cancer death was observed for higher BP levels (HR, 1.05; 95% CI, 1.01-1.08) per SD of mid-BP; however, the association was restricted to distant metastatic disease (Pheterogeneity between case groups = 0.01), and there was no association for BP measured less than 10 years prior to diagnosis.

CONCLUSIONS

Prediagnostic BP is unlikely an important risk factor for prostate cancer development and death. Less asymptomatic PSA testing among men with higher BP levels may explain their lower risk of prostate cancer.

IMPACT

Elevated BP is unlikely to be an important risk factor for prostate cancer.

Zinc and Breast Cancer Survival: A Prospective Cohort Study of Dietary Intake and Serum Levels

Zinc has been suggested to play a role in breast cancer progression; however, no previous study on zinc levels and the potential effect on breast cancer survival has been conducted. This study investigates recurrence-free survival (RFS), breast cancer-specific survival (BCSS) and overall survival (OS) in relation to zinc levels, in serum and diet, overall and stratified for phosphorus and selenium levels. The Malmö Diet and Cancer Study, a prospective population-based cohort in Sweden including 17,035 women, was used to identify breast cancer patients diagnosed in the period 1991–2013. Diet was assessed by a validated modified diet history method. A Cox regression analysis yielded hazard ratios (HRs) with 95% confidence intervals adjusted for potential confounders. Out of 1062 patients with invasive breast cancer, 268 recurrences, 205 breast cancer deaths and 228 deaths from other causes were recorded. No overall associations were seen between zinc and RFS, BCSS or OS. However, in women with a high phosphorus intake, a higher BCSS and OS were seen in zinc intake Q2 to Q4 versus Q1; the adjusted HR was 0.41 (0.23–0.73) and 0.64 (0.41–1.00), respectively. The results indicate that the combination of intermediate/high zinc intake and high phosphorus intake may lead to a better breast cancer survival.

Smoking and Risk of Prostate Cancer and Prostate Cancer Death: A Pooled Study

BACKGROUND

Prospective and detailed investigations of smoking and prostate cancer (PCa) risk and death are lacking.

OBJECTIVE

To investigate prediagnosis smoking habit (status, intensity, duration, and cessation) as a risk factor, on its own and combined with body mass index (BMI), for PCa incidence and death.

DESIGN, SETTING, AND PARTICIPANTS

We included 351448 men with smoking information from five Swedish cohorts.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

We used Cox regression to calculate hazard ratios (HRs) and confidence intervals (CIs) for PCa incidence (n = 24731) and death (n = 4322).

RESULTS AND LIMITATIONS

Smoking was associated with a lower risk of any PCa (HR 0.89, 95% CI 0.86-0.92), which was most pronounced for low-risk PCa (HR 0.74, 95% CI 0.69-0.79) and was restricted to PCa cases diagnosed in the prostate-specific antigen (PSA) era. Smoking was associated with a higher risk of PCa death in the full cohort (HR 1.10, 95% CI 1.02-1.18) and in case-only analysis adjusted for clinical characteristics (HR 1.20, 95% CI 1.11-1.31), which was a consistent finding across case groups (p = 0.8 for heterogeneity). Associations by smoking intensity and, to lesser degree, smoking duration and cessation, supported the associations for smoking status. Smoking in combination with obesity (BMI ≥30 kg/m²) further decreased the risk of low-risk PCa incidence (HR 0.40, 95% CI 0.30-0.53 compared to never smokers with BMI <25 kg/m²) and further increased the risk of PCa death (HR 1.49, 95% CI 1.21-1.84). A limitation of the study is that only a subgroup of men had information on smoking habit around the time of their PCa diagnosis.

CONCLUSIONS

The lower PCa risk for smokers in the PSA era, particularly for low-risk PCa, can probably be attributed to low uptake of PSA testing by smokers. Poor survival for smokers, particularly obese smokers, requires further study to clarify the underlying causes and the preventive potential of smoking intervention for PCa death.

PATIENT SUMMARY

Smokers have a higher risk of dying from prostate cancer, which further increases with obesity.

Association between Adherence to Swedish Dietary Guidelines and Mediterranean Diet and Risk of Stroke in a Swedish Population

Dietary factors associated with stroke risk are still rather unknown. The aim was to examine the association between adherence to healthy dietary patterns and incidence of stroke among 25,840 individuals from the Swedish Malmö Diet and Cancer Study cohort. Dietary data were obtained using a combination of a 7-day food record, diet questionnaire, and interview. A Swedish Dietary Guidelines Score (SDGS), including five dietary components based on the current Swedish dietary guidelines, and a modified Mediterranean diet score (mMDS), composed of ten dietary components, were constructed. Over a mean follow-up period of 19.5 years, 2579 stroke cases, of which 80% were ischaemic, were identified through national registers. Weak, non-significant associations were found between the dietary indices and the risk of stroke. However, after excluding potential misreporters and individuals with unstable food habits (35% of the population), we observed significant inverse association (p-trend < 0.05) between SDGS and mMDS and total and ischaemic stroke (HR per point for total stroke: 0.96; 95% CI: 0.92−1.00 for SDGS and 0.95; 95% CI: 0.91−0.99 for mMDS). In conclusion, high quality diet in line with the current Swedish dietary recommendations or Mediterranean diet may reduce the risk of total and ischaemic stroke.

Development of an EAT-Lancet index and its relation to mortality in a Swedish population

BACKGROUND

Current global food systems threaten human health and environmental sustainability. In 2019, the EAT-Lancet Commission on healthy diets from sustainable food systems defined the first global reference diet to improve both areas, but there is no consensus on how to quantify the EAT-Lancet reference diet as a diet index, and its relation to mortality has not been widely studied.

OBJECTIVES

We sought to develop a new dietary index to quantify adherence to the EAT-Lancet diet and assess its association with mortality in a large, population-based Swedish cohort. We also examined food components included in the index and their individual associations with mortality.

METHODS

We used the Malmö Diet and Cancer cohort (n = 22,421; 45-73 years old at baseline). Dietary data were collected using a modified diet history method. The EAT-Lancet index was developed based on intake levels and reference intervals of 14 food components defined in the EAT-Lancet diet (0-3 points per component; 0-42 points in total). Associations with mortality were examined based on registers during a mean of 20 years of follow-up and were adjusted for potential confounders.

RESULTS

Divided into 5 adherence groups, the highest adherence to the EAT-Lancet diet (≥23 points) was associated with lower all-cause mortality (HR, 0.75; 95% CI, 0.67-0.85), cancer mortality (HR, 0.76; 95% CI, 0.63-0.92), and cardiovascular mortality (HR, 0.68; 95% CI, 0.54-0.84) than the lowest adherence (≤13 points). Several food components included in the index contributed to the observed reductions in mortality.

CONCLUSIONS

We developed a new dietary index to investigate adherence to the EAT-Lancet diet. The findings indicate a 25% lower risk of mortality among those with the highest adherence to the EAT-Lancet diet, as defined using our index, which adds to the evidence base for the development of sustainable dietary guidelines.

Genetic Variation Interacts with Selenium Exposure Regarding Breast Cancer Risk: Assessing Dietary Intake, Serum Levels and Genetically Elevated Selenium Levels

Selenium has been suggested to be protective regarding breast cancer risk but no overall effect has been established. Genetics may modify the effect. This study compares the effect of selenium exposure on breast cancer risk between women with different alleles in single-nucleotide polymorphisms (SNPs). The Malmö Cancer and Diet Study, a cohort including 17,035 women and >25 years of follow-up on breast cancer diagnosis, was used. Five promising SNPs regarding interaction with selenium exposure were selected from the literature: rs1050450, rs4880, rs3877899, rs7579, and rs71304. Selenium exposure was assessed in three ways: genetically elevated (n = 16,429), dietary intake (n = 15,891) and serum levels (n = 2037) at baseline. Cox regression and logistic regression analyses evaluated breast cancer risk from selenium exposure, stratified for the SNPs and adjusted for risk factors. A total of 1946 women were diagnosed with breast cancer. Women with T/T alleles in rs1050450 had lower breast cancer risk compared with C/C, HR 0.81 (0.68–0.96). Interaction by rs1050450 limited a protective effect of higher selenium intake to T/T carriers, HR 0.68 (0.43–1.08) for intermediate intake and HR 0.63 (0.40–1.00) for high intake. No interactions or risk differences were seen for other SNPs or for serum selenium or genetically elevated selenium. The results indicate that genetic variation in rs1050450 might affect breast cancer risk and that selenium exposure could be a possible modifiable risk factor for breast cancer among women with that variation.

Characteristics associated between the incidence of hip osteoarthritis and early hip complaints (CHECK study) within 10 years

OBJECTIVE

To determine which baseline characteristics, especially clinically variables like pain, stiffness, physical functioning and disease variables, are associated with incident hip OA within 10 years in first presenters with hip complaints. Rheumatology key messages History taking and not physical exam variables are associated with incident hip osteoarthritis. Specific questions about daily life activities are associated with incident hip OA. These questions are about pain while walking/shopping, difficulties putting socks on/off and rising from bed.

METHODS

Data were obtained from the nationwide prospective Cohort Hip and Cohort Knee (CHECK) study (n = 1002). Incident hip OA was defined as fulfilling the clinical ACR criteria for hip OA, a Kellgren and Lawrence score ≥2 with hip pain, or received a hip replacement during follow-up. Baseline measurements were used of participants with hip complaints and without hip OA. Principal component analysis (PCA) was used to reduce the number of correlated variables. Associations between baseline characteristics (including PCA components) and incident hip OA were investigated using logistic regression analysis, adjusted for age, sex and BMI.

RESULTS

In total, 312 participants (85% female and 98% Caucasian) were included, 181 developed hip OA. PCA resulted in four components. Incident hip OA was associated with (i) component 1 (general presence of pain and symptoms) [odds ratio (OR) = 1.46 (95%CI: 1.08, 1.98)], (ii) component 3 (relatively high levels of pain during shopping/walking combined with less difficulty with putting socks on/off and rising from bed) [OR = 1.58 (95%CI: 1.18, 2.12)] and (iii) knee pain [OR = 0.34 (95% CI: 0.17, 0.66)].

CONCLUSION

In first presenters with hip complaints, use of a few history-taking variables might allow better recognition of those at higher odds for incident hip OA within 10 years.

Diabetes Mellitus as a Risk Factor for Trigger Finger –a Longitudinal Cohort Study Over More Than 20 Years

Background and Aim

Trigger finger (TF) or stenosing tenosynovitis has been associated with diabetes mellitus (DM), although today’s knowledge is mostly based on cross-sectional and case-control studies. Thus, the aim of the present population-based cohort study over more than 20 years was to investigate DM as a risk factor for TF.

Methods

Data from Malmö Diet and Cancer Study (MDCS), including 30,446 individuals, were analysed with regards to baseline DM and known or potential confounders. Information regarding TF diagnosis until study end date of Dec 31st, 2018, was retrieved from the Swedish National Patient Register (NPR) using ICD-codes. Survival probability was investigated in Kaplan-Meier plots. Cox proportional hazard regression model was used to evaluate DM as risk factor for TF, adjusted for several confounders and presented as Hazard Ratio (HR) with 95% confidence intervals (CI).

Results

At baseline, 4.6% (1,393/30,357) participants had DM. In total, 3.2% (974/30,357) participants were diagnosed with TF during the study period. Kaplan-Meier plot showed that the probability for incident TF was significantly higher in participants with baseline DM compared with individuals without baseline DM. Adjusted HR for DM as risk factor for TF was 2.0 (95% CI: 1.5-2.6, p&lt;0.001).

Conclusion

This longitudinal study showed that DM is an important risk factor for developing TF. When adjusting for sex, age, BMI, manual work, statin use, smoking and alcohol consumption, DM remained the main risk factor for TF.

Leisure-time physical activities and the risk of cardiovascular mortality in the Malmö diet and Cancer study

Background

The association between leisure-time physical activity and cardiovascular mortality has been previously studied, but few studies have focused on specific activities and intensities.

Methods

The association between different leisure-time physical activities and cardiovascular mortality was investigated among 25,876 individuals without diabetes or cardiovascular disease from the population-based Malmö Diet and Cancer Study cohort. The individuals estimated the average duration spent on 17 physical activities at baseline in 1991–1996 and after 5 years. Cardiovascular mortality was obtained from a register during a mean of 20 years of follow-up.

Results

A total leisure-time physical activity of 15–25 metabolic equivalent task (MET) hours/week was associated with a decreased risk of cardiovascular mortality (HR 15–25 vs < 7.5 MET-h/week =0.80, 95% CI 0.69–0.93), with no further risk reduction at higher levels. Several high-intensity activities (i.e., lawn tennis and running) and moderate-intensity activities (i.e., golf, cycling and gardening) were associated with a reduced risk. Individuals who engaged in high-intensity physical activity for an average of 2.29 MET h/week (30 min/week) had an 18% (95% CI 0.72–0.93) reduced risk of cardiovascular mortality compared with non-participants, and no further risk reductions were observed at higher levels. Decreased risk was observed among individuals who had started (HR 0.56, 95% CI 0.32–0.97) or continued (HR 0.49, 95% CI 0.36–0.66) high-intensity activities at the five-year follow-up.

Conclusions

Moderate- and high-intensity leisure-time physical activities reduced the risk of cardiovascular mortality. With regard to total leisure-time physical activity, the largest risk reduction was observed for 15–25 MET-h/week (equivalent to walking for approximately 5 h/week).

Carotid-Femoral Pulse Transit Time Variability Predicted Mortality and Improved Risk Stratification in the Elderly

[Figure: see text].

Metabolic factors and the risk of Dupuytren's disease: data from 30,000 individuals followed for over 20 years

Dupuytren’s disease (DD) is a fibroproliferative disorder affecting the palmar fascia of the hand. Risk factors include diabetes mellitus (DM), whereas a high body mass index (BMI) is associated with a lower prevalence of DD. The aim of this study was to further elucidate risk and protective factors for the development of DD using longitudinal population-based data from the Malmö Diet and Cancer Study (MDCS). During 1991–1996, the inhabitants aged 46–73 years in the city of Malmö, Sweden were invited to participate in the population-based MDCS (41% participation rate). Data on incident DD were retrieved from Swedish national registers. Associations between DM, alcohol consumption, BMI, and serum apolipoprotein A1 (ApoA1) and apolipoprotein B (ApoB) at baseline were analysed in multivariable Cox regression models adjusted for known confounders. Among 30,446 recruited participants, 347 men and 194 women were diagnosed with DD during a median follow-up time of 23 years. DM (men HR 2.23; 95% CI 1.50–3.30, women HR 2.69; 95% CI 1.48–4.90) and alcohol consumption (men HR 2.46; 95% CI 1.85–3.27, women HR 3.56; 95% CI 1.95–6.50) were independently associated with incident DD in the Cox regression models. Furthermore, inverse associations with incident DD were found for obesity among men, and ApoB/ApoA1 ratio among both sexes. DM and excess alcohol consumption constituted major risk factors for the development of DD. Furthermore, an inverse association between obesity among men and DD, and also between ApoB/ApoA1 ratio and DD was found in both sexes.

Serum zinc and dietary intake of zinc in relation to risk of different breast cancer subgroups and serum levels as a marker of intake: a prospective nested case-control study

PURPOSE

Zinc has been suggested to be protective against breast cancer, but the evidence remains inconclusive. One reason for inconsistent findings in previous studies may be that zinc only influences the risk of developing certain subtypes of breast cancer. Our study is the first study assessing zinc levels in relation to the risk of different breast cancer subgroups, defined by their tumor characteristics. In addition, we analyze serum zinc as a marker of dietary intake.

METHODS

The Malmö Diet and Cancer Study is a population-based cohort study that took place 1991-1996 in Malmö, Sweden. Until end of follow-up, 31 December 2013, 1186 incident cases were identified and matched to an equal number of controls. Odds ratios (ORs) for breast cancer, and having a certain tumor characteristic, were estimated in quartiles of baseline serum zinc and zinc intake and adjusted for potential confounders.

RESULTS

No associations were found between zinc, measured in serum or diet pre-diagnostically, and breast cancer risk. The adjusted OR for breast cancer in serum zinc Q4 compared to Q1 was 1.09 (0.85-1.41) and in zinc intake Q4 versus Q1 was 0.97 (0.77-1.23). Moreover, there were no clear associations between zinc and any breast cancer characteristics. The kappa value, 0.025 (P = 0.022), showed poor agreement between serum zinc and zinc intake.

CONCLUSION

Our findings indicate that there is no clear association between zinc and overall breast cancer risk or risk of different breast cancer subgroups. Finally, our results suggest that serum zinc is a poor marker of zinc intake.

Modifiable and Non-Modifiable Risk Factors for Atherothrombotic Ischemic Stroke among Subjects in the Malmö Diet and Cancer Study

Risk factors for ischemic stroke is suggested to differ by etiologic subtypes. The purpose of this study was to examine the associations between modifiable and non-modifiable risk factors and atherothrombotic stroke (i.e., excluding cardioembolic stroke), and to examine if the potential benefit of modifiable lifestyle factors differs among subjects with and without predisposing comorbidities. After a median follow-up of 21.2 years, 2339 individuals were diagnosed with atherothrombotic stroke out of 26,547 study participants from the Malmö Diet and Cancer study. Using multivariable Cox regression, we examined non-modifiable (demographics and family history of stroke), semi-modifiable comorbidities (hypertension, dyslipidemia, diabetes mellitus and atherosclerotic disease), and modifiable (smoking, body mass index, diet quality, physical activity, and alcohol intake) risk factors in relation to atherothrombotic stroke. Higher age, male gender, family history of stroke, and low educational level increased the risk of atherothrombotic stroke as did predisposing comorbidities. Non-smoking (hazard ratio (HR) = 0.62, 95% confidence interval (CI) 0.56–0.68), high diet quality (HR = 0.83, 95% CI 0.72–0.97) and high leisure-time physical activity (HR = 0.89, 95% CI 0.80–0.98) decreased the risk of atherothrombotic ischemic stroke independent of established risk factors, with non-significant associations with body mass index and alcohol intake. The effect of the lifestyle factors was independent of predisposing comorbidities at baseline. The adverse effects of several cardiovascular risk factors were confirmed in this study of atherothrombotic stroke. Smoking cessation, improving diet quality and increasing physical activity level is likely to lower risk of atherothrombotic stroke in the general population as well as in patient groups at high risk.

"Association of mammographic features with molecular breast tumor profiles"

PURPOSE

Mammographic density and tumor appearance are breast cancer prognostic factors. Conceivably, mammographic features are macroscopic reflections of tumor´s molecular composition, but to an unknown extent. Our aim was to study associations of mammographic features with molecular tumor profiles.

METHODS

Invasive breast cancers (2007-2016) in Malmö Diet and Cancer Study (MDCS) for which there were tumor RNA-sequencing analyses within Sweden Cancerome Analysis Network - Breast (SCAN-B) (n=102) or All Breast Cancer in Malmö (ABIM) (n=50) were identified. Density (fatty vs. dense), tumor appearance (mass vs. spiculation), and intrinsic subtypes were registered. Differences in gene/metagene expression and Microenvironment Cell Population Counter were analyzed with R. Overall survival was used as endpoint.

RESULTS

No gene expression differences between density groups was observed. In one cohort (but not the other), Luminal A tumors associated with fatty breasts. For spiculation vs. mass, (p<0.01, t-test) 86 genes were differentially expressed; only one gene was differentially expressed comparing density. Gene set enrichment analysis showed genes highly expressed in spiculated tumors were enriched for extracellular matrix-associated genes whereas genes highly expressed with masses were associated with proliferation. A spiculation metagene, based on differentially expressed genes, showed association with estrogen receptor positivity, lower grade, and improved survival, but it was not an independent prognostic factor.

CONCLUSION

There are clear differences in molecular composition between breast tumors with a spiculated appearance vs. a mass as the dominant tumor appearance. However, there are no apparent molecular differences related to the density of the breast in which the tumor has arisen.

Examination of Cancer and Aging Through Activities of Daily Living: A National Health and Aging Trends Study Analysis

Objectives: This study longitudinally examined how older adult cancer survivors perceive disability in activities of daily living over time compared to older adults who have not had cancer. Methods: This was a secondary analysis of the National Health and Aging Trends Study examining participants with a new cancer diagnosis and age-, gender-, and comorbidity-matched comparison participants without a history of cancer. Generalized linear mixed models examined time and group interaction and main effects in disability. Results: There was a significant main effect of time (F_4,771 = 12.81; p < .0001) demonstrating increasing disability levels for both groups. There were significant group differences, with higher disability in the cancer group than the comparison group (β = 0.628, SE = 0.263; t = 2.39, p = 0.017). Discussion: Although perceived disability was greater immediately following cancer diagnosis, older adult cancer survivors and comparison participants appear to have similar perceived disability over time.

Association between Sugar Intake and Intima Media Thickness as a Marker for Atherosclerosis: A Cross-Sectional Study in the Malmö Diet and Cancer Study (Sweden)

It has been suggested that sugar intake may play a role in the development of atherosclerosis. However, studies on this matter are lacking. Intima media thickness (IMT) is a well-established measurement of subclinical atherosclerosis. This study aimed to investigate the cross-sectional association between sugar intake (i.e., added, free and total sugar and sugar-rich foods and beverages) and IMT. Our study comprised 5269 individuals (45–73 years, 40% men) of the Malmö Diet and Cancer Study, a population-based cohort conducted in Sweden with data collected from 1991 to 1994. Measurements of IMT were performed with B-mode ultrasound at the right common carotid artery (IMTcca) and the bifurcation of the carotids (IMTbif). Dietary intake was estimated using a combination of a 7-day food record, diet questionnaire and interview. After adjusting for methodological, lifestyle and dietary confounders, no statistically significant associations were observed for any of the sugar intake variables and IMT. For example, added sugar intake presented no significant linear association with IMTcca or IMTbif (P_trends: IMTcca 0.81 for men and 0.98 for women and IMTbif 0.20 for men and 0.40 for women). In conclusion, we found no clear association between sugar intake and IMT measurements in this study.

Risk of breast cancer in relation to dietary intake of selenium and serum selenium as a marker of dietary intake: a prospective cohort study within The Malmö Diet and Cancer Study

Purpose

Selenium has been suggested to be protective against breast cancer, but the evidence remains inconclusive. Hence, it is important to further examine the potential protective effect. This prospective cohort study investigates pre-diagnostic selenium intake in relation to breast cancer risk. In addition, we analyze serum selenium as a marker of dietary intake.

Methods

This study includes 17,035 women in the Malmö Diet and Cancer cohort. Dietary assessment and serum samples were collected at baseline (1991–1996). During 344,584 person-years of follow-up, 1,427 incident cases were retrieved. Cox regression analysis examined breast cancer risks adjusted for potential confounding factors. In addition, odds ratios (ORs) were estimated for 1186 cases and an equal number of controls in relation to quartiles (Q) of selenium intake and groups consisting of a combination of intake and serum selenium levels.

Results

No overall association between selenium intake, or a combination of intake and serum levels, and breast cancer risk was found. The adjusted relative risk for breast cancer in selenium intake Q4 versus Q1 was 0.96 (0.83–1.12) (P_trend = 0.65). Similarly, adjusted the OR for breast cancer in selenium intake for Q4 versus Q1 was 0.97 (0.76–1.23). The kappa value, 0.096 (p = 0.001), showed poor agreement between serum selenium and selenium intake.

Conclusion

Our findings suggest that there is no overall association between selenium intake, or a combination of intake and serum levels, and breast cancer risk. Finally, our results showed a poor correlation between estimated selenium intake and serum selenium.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10552-021-01433-1.

Methodological considerations for identifying multiple plasma proteins associated with all-cause mortality in a population-based prospective cohort

Novel methods to characterize the plasma proteome has made it possible to examine a wide range of proteins in large longitudinal cohort studies, but the complexity of the human proteome makes it difficult to identify robust protein-disease associations. Nevertheless, identification of individuals at high risk of early mortality is a central issue in clinical decision making and novel biomarkers may be useful to improve risk stratification. With adjustment for established risk factors, we examined the associations between 138 plasma proteins measured using two proximity extension assays and long-term risk of all-cause mortality in 3,918 participants of the population-based Malmö Diet and Cancer Study. To examine the reproducibility of protein-mortality associations we used a two-step random-split approach to simulate a discovery and replication cohort and conducted analyses using four different methods: Cox regression, stepwise Cox regression, Lasso-Cox regression, and random survival forest (RSF). In the total study population, we identified eight proteins that associated with all-cause mortality after adjustment for established risk factors and with Bonferroni correction for multiple testing. In the two-step analyses, the number of proteins selected for model inclusion in both random samples ranged from 6 to 21 depending on the method used. However, only three proteins were consistently included in both samples across all four methods (growth/differentiation factor-15 (GDF-15), N-terminal pro-B-type natriuretic peptide, and epididymal secretory protein E4). Using the total study population, the C-statistic for a model including established risk factors was 0.7222 and increased to 0.7284 with inclusion of the most predictive protein (GDF-15; P < 0.0001). All multiple protein models showed additional improvement in the C-statistic compared to the single protein model (all P < 0.0001). We identified several plasma proteins associated with increased risk of all-cause mortality independently of established risk factors. Further investigation into the putatively causal role of these proteins for longevity is needed. In addition, the examined methods for identifying multiple proteins showed tendencies for overfitting by including several putatively false positive findings. Thus, the reproducibility of findings using such approaches may be limited.

Waist circumference and a body shape index and prostate cancer risk and mortality

We recently found a negative association between body mass index (BMI) and the risk of localised prostate cancer (PCa), no association with advanced PCa, and a positive association with PCa‐specific mortality. In a 15% subpopulation of that study, we here investigated the measures of abdominal adiposity including waist circumference (WC) and A Body Shape Index (ABSI) in relation to PCa risk and mortality. We used data from 58,457 men from four Swedish cohorts to assess WC and ABSI in relation to PCa risk according to cancer risk category, including localised asymptomatic and symptomatic PCa and advanced PCa, and PCa‐specific mortality. Cox regression models were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs). During, on average, 10 years of follow‐up, 3290 men were diagnosed with PCa and 387 died of PCa. WC was negatively associated with the risk of total PCa (HR per 10 cm, 0.95; 95% CI 0.92–0.99), localised PCa (HR per 10 cm, 0.93, 95% CI 0.88–0.96) and localised asymptomatic PCa cases detected through a prostate‐specific antigen (PSA) test (HR per 10 cm, 0.87, 95% CI 0.81–0.94). WC was not associated with the risk of advanced PCa (HR per 10 cm, 1.02, 95% CI 0.93–1.14) or with PCa‐specific mortality (HR per 10 cm, 1.04, 95% CI 0.92–1.19). ABSI showed no associations with the risk of PCa or PCa‐specific mortality. While the negative association between WC and the risk of localised PCa was partially driven by PSA‐detected PCa cases, no association was found between abdominal adiposity and clinically manifest PCa in our population.

Interaction Effect Between Copy Number Variation in Salivary Amylase Locus (AMY1) and Starch Intake on Glucose Homeostasis in the Malmö Diet and Cancer Cohort

Salivary amylase initiates the digestion of starch and it has been hypothesized that salivary amylase may play a role in the development of insulin resistance and type 2 diabetes. The aim was to examine the interaction between copy number variation in the salivary amylase gene AMY1 and starch intake. We studied 3,624 adults without diabetes or elevated blood glucose in the Malmö Diet Cancer cohort. We assessed the associations and interactions between starch intake, AMY1 copies and glucose homeostasis traits (i.e., fasting plasma glucose, insulin and HOMA-IR) and risk of type 2 diabetes over an average of 18 follow-up years. AMY1 copy number was not associated with glucose, insulin or HOMA-IR. We observed a significant interaction between starch intake and AMY1 copies on insulin and HOMA-IR after adjusting for potential confounders (p < 0.05). The inverse association between starch intake and insulin and HOMA-IR was stronger in the group with 10 or more copies (P _trend < 0.001). In addition, we observed an inverse association between starch intake and type 2 diabetes in the group with 10 or more copies (p _trend = 0.003), but not in the other groups. This cross-sectional observational study suggests that AMY1 copy numbers might interact with starch intake on glucose homeostasis traits. Interventional studies are required to determine whether individuals with high AMY1 copy numbers may benefit from a high starch intake.

Mammographic tumour appearance is related to clinicopathological factors and surrogate molecular breast cancer subtype

Mammographic tumour appearance may provide prognostic useful information. For example, spiculation indicates invasiveness, but also better survival compared to tumours with other appearances. We aimed to study the relationship between mammographic tumour appearance and established clinicopathological factors, including surrogate molecular breast cancer subtypes, in the large Malmö Diet and Cancer Study. A total of 1116 women with invasive breast cancer, diagnosed between 1991 and 2014, were included. Mammographic tumour appearance in relation to status for oestrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2, histological grade, Ki67 and molecular subtype was analysed using various regression models. All models were adjusted for relevant confounders, including breast density, which can affect mammographic appearance. The results consistently showed that spiculated tumours are indicative of favourable characteristics, as they are more likely to be ER and PR positive, and more often exhibit lower histological grade and lower Ki67 expression. Furthermore, spiculated tumours tend to be of luminal A-like subtype, which is associated with a good prognosis. The establishment of associations between mammographic tumour appearance and clinico­pathological factors may aid in characterizing breast cancer at an earlier stage. This could contribute to more individualized breast cancer treatment in the future.

Association between dietary fiber intake and risk of incident aortic stenosis

BACKGROUND AND AIMS

Although aortic stenosis is the most common valvular heart disease requiring intervention in Europe, the role that diet plays in development of the disease is largely unknown. The pathophysiology of aortic stenosis is however similar to other cardiovascular diseases that fiber intake has been associated with. The aim of this study was consequently to investigate the association between dietary fiber intake as well as the main food sources of fiber, i.e. fruit and vegetables and whole grains, and risk of incident aortic stenosis.

METHODS AND RESULTS

The Malmö Diet and Cancer Study is a Swedish prospective population-based cohort study with baseline data collection performed between year 1991-1996. Dietary habits were recorded through seven-day food diaries, 168-item diet questionnaires, and interviews, and data on incident aortic stenosis was collected through national registers. Among the 26,063 participants, 672 cases were ascertained during a mean follow-up period of 20 years. Cox regression was used to estimate the association between dietary intakes and incident aortic stenosis. No associations were found between incident aortic stenosis and intake of dietary fiber (HR for the highest vs lowest quintile: 0.93; 95% CI: 0.72-1.24), fruit and vegetables (HR: 0.98; 95% CI: 0.76-1.28), or whole grains (HR: 1.00; 95% CI: 0.79-1.26) in the main model.

CONCLUSION

The findings of this study do not indicate that consumption of dietary fiber or fiber rich foods are associated with incident aortic stenosis.

Alpha-amylase 1A copy number variants and the association with memory performance and Alzheimer's dementia

Background

Previous studies have shown that copy number variation (CNV) in the alpha (α)-amylase gene (AMY1A) is associated with body mass index, insulin resistance, and blood glucose levels, factors also shown to increase the risk of Alzheimer’s dementia (AD). We have previously demonstrated the presence of α-amylase in healthy neuronal dendritic spines and a reduction of the same in AD patients. In the current study, we investigate the relationship between AMY1A copy number and AD, memory performance, and brain α-amylase activity.

Methods and materials

The association between AMY1A copy number and development of AD was analyzed in 5422 individuals (mean age at baseline 57.5 ± 5.9, females 58.2%) from the Malmö diet and cancer study genotyped for AMY1A copy number, whereof 247 where diagnosed with AD during a mean follow-up of 20 years. Associations between AMY1A copy number and cognitive performance where analyzed in 791 individuals (mean age at baseline 54.7 ± 6.3, females 63%), who performed Montreal Cognitive Assessment (MoCA) test. Correlation analysis between α-amylase activity or α-amylase gene expression and AMY1A copy number in post-mortem hippocampal tissue from on demented controls (n = 8) and AD patients (n = 10) was also performed.

Results

Individuals with very high ( ≥10) AMY1A copy number had a significantly lower hazard ratio of AD (HR = 0.62, 95% CI 0.41–0.94) and performed significantly better on MoCA delayed word recall test, compared to the reference group with AMY1A copy number 6. A trend to lower hazard ratio of AD was also found among individuals with low AMY1A copy number (1–5) (HR = 0.74, 95% CI 0.53–1.02). A tendency towards a positive correlation between brain α-amylase activity and AMY1A copy number was found, and females showed higher brain α-amylase activity compared to males.

Conclusion

Our study suggests that the degree of α-amylase activity in the brain is affected by AMY1A copy number and gender, in addition to AD pathology. The study further suggests that very high AMY1A copy number is associated with a decreased hazard ratio of AD and we speculate that this effect is mediated via a beneficial impact of AMY1A copy number on episodic memory performance.

Pro B-type Natriuretic Peptide and Midregional Proadrenomedullin are Associated with Incident Carotid Stenosis During Long Term Follow-up

BACKGROUND

Plasma biomarkers may be useful to detect healthy individuals at increased risk for atherosclerotic manifestations, such as carotid artery stenosis. The aim of this longitudinal cohort study was to evaluate new biomarkers in relation to C-reactive protein and conventional risk factors for carotid artery stenosis during long term follow-up METHODS: The following markers were measured in 5550 middle-aged subjects: C-reactive protein, lipoprotein-associated phospholipase A2, proneurotensin, midregional pro-adrenomedullin, midregional pro-atrial natriuretic peptide, N-terminal pro B-type natriuretic peptide, copeptin, and cystatin C. Subjects with prevalent carotid artery stenosis were excluded. Subjects were followed in national patient registers for 23.4 (interquartile range 19.5-24.3) years regarding incident carotid artery stenosis, both operated and non-operated.

RESULTS

When including conventional risk markers in Cox regression, N-terminal pro B-type natriuretic peptide (Hazard ratio 1.36; 95% confidence interval 1.12-1.65; p = 0.002) was independently associated with incident carotid artery stenosis, whereas there were trends for C-reactive protein (HR 1.20; 95% confidence interval 0.98-1.48; p = 0.071), and midregional pro-adrenomedullin (Hazard ratio 1.21; 95% confidence interval 0.99-1.47; p = 0.061). Midregional pro-adrenomedullin (Hazard ratio 1.30; 95% confidence interval 1.03-1.65; p = 0.029) was independently associated with incident surgery for carotid artery stenosis, whereas there was a trend for N-terminal pro B-type natriuretic peptide (Hazard ratio 1.31; 95% confidence interval 1.00-1.72; p = 0.052).

CONCLUSIONS

N-terminal pro B-type natriuretic peptide and midregional pro-adrenomedullin can be used as predictors for clinically detected carotid artery stenosis during long-term follow-up of healthy subjects.

The association of single nucleotide polymorphisms (SNPs) with breast density and breast cancer survival: the Malmö Diet and Cancer Study

Background

Genetic factors are important in determining breast density, and heritable factors account for 60% of the variation. Certain single nucleotide polymorphisms (SNPs) are associated with density and risk of breast cancer but the association with prognosis is not clear.

Purpose

To investigate associations between selected SNPs and breast cancer survival in the Malmö Diet and Cancer Study (MDCS).

Material and Methods

A total of 724 unrelated women with breast cancer and registered radiological and pathological data were identified in MDCS 1991–2007, with genotyping available for 672 women. Associations among 15 SNPs, density, and breast cancer-specific survival were analyzed using logistic/Cox regression, adjusted for factors affecting density and survival. Variants significantly associated with either density or survival were validated in a large independent breast cancer cohort (LIBRO-1).

Results

Minor homozygotes of SNPs rs9383589, CCDC170 and rs6557161, ESR1 were associated with high breast density (adjusted odds ratio [AOR] 8.97, 95% confidence interval [CI] 1.35–59.57; AOR 2.08, 95% CI 1.19–3.65, respectively) and poorer breast cancer survival (adjusted hazard ratio [HR_adj] 6.46, 95% CI 1.95–21.39; HR_adj 2.30, 95% CI 1.33–3.96, respectively) compared to major homozygotes. For SNP rs3757318, ESR1, minor homozygotes (HR_adj 7.46, 95% CI 2.28–24.45) were associated with poorer survival. We confirmed that rs6557161, ESR1 was significantly associated with both density and survival in the LIBRO-1 study.

Conclusion

These findings support a shared genetic basis for density and breast cancer survival. The SNP significantly associated with both density and survival in both cohorts may be of interest in future research investigating polygenic risk scores for breast cancer risk and screening stratification purposes.

Prediagnostic serum selenium levels in relation to breast cancer survival and tumor characteristics

Women with lower levels of serum selenium (Se) may have a worse survival in breast cancer than women with higher levels, despite no difference in incidence of the disease. Our study was conducted to test whether Se is associated with the aggressiveness of breast tumors. Both the risk of having a tumor characteristic associated with worse prognosis, as well as the overall and breast cancer-specific mortality, were studied. We identified breast cancer cases and controls within the Malmö Diet and Cancer Study, a population-based cohort with 17 035 women recruited between 1991 and 1996. Inclusion criteria were incident breast cancer. Exclusion criteria were carcinoma in situ and bilateral breast cancer. Controls were selected among breast cancer-free women both from matching (n = 694) as well as randomization (n = 492). After exclusion, 1066 cases remained and were compared to controls regarding their prediagnostic serum Se levels and subsequent risk of having a certain tumor characteristic or intrinsic subtype. We also followed breast cancer patients regarding overall and breast cancer-specific mortality, comparing different Se quartiles. No association between serum Se quartile and any tumor characteristic or intrinsic subtype was found. Lower overall mortality was found among women in the highest Se quartile compared to the lowest using an adjusted Cox proportional hazards model, hazard ratio 0.63 (95% confidence interval: 0.44-0.89). Similar results were seen for breast cancer-specific mortality, 0.60 (0.37-0.98). The results of our study support that Se is associated with a lower mortality in breast cancer, not related to established prognostic factors.

Ovarian cancer subtypes and survival in relation to three comprehensive imaging parameters

Background

Ovarian cancer (OC) is usually detected in late clinical stages, and imaging at diagnosis is crucial. Peritoneal carcinomatosis (PC) and cardio phrenic lymph nodes (CPLN) are pathological findings of computed tomography (CT) and are relevant for surgical planning. Furthermore, mammographic breast density (BD) has shown an association with OC risk and might be prognostically relevant. However, it is not known if PC, CPLN, and BD are associated with aggressive OC subtypes and impaired OC survival. Herein, we investigated associations between three comprehensive image parameters and OC subtypes and survival.

Methods

The Malmö Diet and Cancer Study is a prospective study that included 17,035 women (1991–1996). Tumor information on 159 OC and information on OC specific survival (last follow-up, 2017-12-31) was registered. The CT and mammography closest to diagnosis were evaluated (Peritoneal Carcinomatosis Index PCI, CPLN, and BD). Associations between CT-PCI, CPLN, and BD vs. clinical stage [stage I vs. advanced stage (II-IV), histological type/grade (high grade serous and endometrioid vs. other subtypes], and OC-specific survival were analyzed by logistic and Cox regression.

Results

There was a significant association between higher CT-PCI score and advanced clinical stage (adjusted OR 1.26 (1.07–1.49)), adjusted for age at diagnosis and histological type/grade. Increasing CT-PCI was significantly associated with impaired OC specific survival (adjusted HR 1.04 (1.01–1.07)), adjusted for age at diagnosis, histological type/grade, and clinical stage. There was no significant association between PCI and histological type/grade, nor between BD or CPLN vs. the studied outcomes.

Conclusions

Image PCI score was significantly associated with advanced clinical stages and impaired OC survival. An objective approach (based on imaging) to scoring peritoneal carcinomatosis in ovarian cancer could help surgeons and oncologists to optimize surgical planning, treatment, and care.

Different domains of self-reported physical activity and risk of type 2 diabetes in a population-based Swedish cohort: the Malmö diet and Cancer study

BACKGROUND

While a dose-response relationship between physical activity and risk of diabetes has been demonstrated, few studies have assessed the relative importance of different measures of physical activity on diabetes risk. The aim was to examine the association between different self-reported measures of physical activity and risk of type 2 diabetes in a prospective cohort study.

METHODS

Out of 26,615 adults (45-74 years, 60% women) in the population-based Swedish Malmö Diet and Cancer Study cohort, 3791 type 2 diabetes cases were identified from registers during 17 years of follow-up. Leisure-time (17 activities), occupational and domestic physical activity were assessed through a questionnaire, and these and total physical activity were investigated in relation to type 2 diabetes risk.

RESULTS

All physical activity measures showed weak to modest associations with type 2 diabetes risk. The strongest association was found in the lower end of leisure-time physical activity in dose-response analysis at levels approximately below 22 MET-hrs/week (300 min/week) representing around 40% of the population. Compared with the lowest quintile, the moderate leisure-time physical activity category had a 28% (95% CI: 0.71, 0.87) decreased risk of type 2 diabetes. Total physical activity showed a similar, but weaker, association with diabetes risk as to that of leisure-time physical activity. Domestic physical activity was positively and linearly related to diabetes risk, HR = 1.11 (95% CI: 0.99, 1.25) comparing highest to lowest quintile. There was no association between occupational physical activity and diabetes risk.

CONCLUSION

A curvilinear association was observed between leisure-time physical activity and risk of diabetes. Beyond a threshold level of approximately 22 MET-hrs/week or 300 min/week, no additional risk reduction was observed with increase in physical activity.

Association between added sugar intake and micronutrient dilution: a cross-sectional study in two adult Swedish populations

Background

The evidence on the impact of high sugar consumption on micronutrient dilution does not yet allow for the establishment of clear thresholds of consumption. To establish upper and lower limit intake thresholds for added sugar, more studies from different countries and multiple populations are needed. The aim of this study was to examine the association between the intakes of added sugar and various micronutrients among the adult Swedish population across almost two decades.

Methods

The data were obtained from the samples from two populations: 1) Riksmaten Adults, a national dietary survey (n = 1797, 44% male, aged 18–80 years, data collection from 2010 to 11) that assessed dietary intake using a 4-day web-based food diary; and 2) the Malmö Diet and Cancer Study, a population-based cohort study (n = 12,238, 45% male, aged 45–68 years, data collection from 1991 to 1994) that assessed dietary intake via a combination of a 7-day food diary, a food frequency questionnaire and an interview. The mean daily intake of nine micronutrients (calcium, folate, iron, magnesium, potassium, selenium, vitamin C, vitamin D, and zinc), adjusted for age, sex, BMI and energy intake, were examined across six added-sugar-intake groups (< 5%E, 5–7.5%E, 7.5–10%E, 10–15%E, 15–20%E, and >  20%E).

Results

We observed significant inverse associations between the intake of added sugar and the intake of all micronutrients in both populations. The associations were linear; however, we could not determine the threshold of added sugar intake beyond which the micronutrient intake was clearly compromised.

Conclusions

These findings suggest that in two Swedish populations the higher the intake of added sugar in the diet, the more likely it is that the intake of micronutrients will be compromised, in two Swedish populations. However, although the trends are significant and consistent with those obtained in other studies on the subject, future studies are needed in order to build the necessary scientific knowledge to establish a threshold of added sugar intake based on micronutrient dilution.

Age at first childbirth and breast cancer survival: a prospective cohort study

OBJECTIVE

Late age at first childbirth is a well-established risk factor for breast cancer. Previous studies have, however, shown conflicting results to whether late age at first childbirth also influences the prognosis of breast cancer survival. The aim of this study was to examine age at first birth in relation to survival after breast cancer diagnosis.

RESULTS

We used information from the Malmö Diet and Cancer study. At baseline 17,035 women were included. All women were followed from the year they developed breast cancer until they either died or until the end of follow-up. All women were asked how many children they had given birth to and were then divided into different groups, ≤ 20, > 20 to  ≤ 25, > 25 to  ≤ 30 and > 30. Nulliparous women form a separate group. Survival analyses were then performed using Cox proportional hazard survival analysis. Women in all age groups had a lower risk of breast cancer specific death as compared to the reference group ≤ 20, however non-significantly. Nulliparous women had a higher risk of breast cancer specific death as compared to the same reference group, however these results were not statistically significant. We could not see any negative effect of late first childbirth on breast cancer specific survival.

Recruitment through media and general practitioners resulted in comparable samples in an RCT on incontinence

OBJECTIVES

The objective of the study was to assess the impact of recruitment strategy on the baseline characteristics of patients recruited in a randomized controlled trial for treating women with urinary incontinence.

STUDY DESIGN AND SETTING

We conducted a cross-sectional analysis of baseline data from an earlier trial. Women were recruited through the media (including social media) or from participating general practices. Baseline characteristics were compared by univariate testing. Logistic regression analysis was performed to study the association between recruitment type and multiple baseline characteristics.

RESULTS

The only differences between recruitment methods were in patient age, with those recruited through the media being significantly older than those recruited through general practice. The mean age difference was 5.0 years (95% confidence interval: 2.2-7.9).

CONCLUSION

Samples recruited through the media and through case identification were largely comparable. Therefore, recruitment through the media may be a viable alternative to recruitment through primary care. This may be especially relevant for research on eHealth treatment for conditions with which patients experience barriers when seeking health care.

A favorable lifestyle lowers the risk of coronary artery disease consistently across strata of non-modifiable risk factors in a population-based cohort

BACKGROUND

A healthy lifestyle has been shown to reduce the risk of coronary artery disease (CAD). The extent to which lifestyle influences the risk of CAD for people with pre-existing non-modifiable risk factors is less studied. We therefore examined the associations between a favorable lifestyle and incidence of CAD in population subgroups based on gender, age, educational level, and parental history of myocardial infarction.

METHODS

A total of 26,323 men and women from the Malmö Diet and Cancer study were prospectively followed-up for 18 years. A favorable lifestyle was determined using a four-component lifestyle score based on data collected at baseline: no smoking, no obesity, regular physical activity, and a healthy diet. Cox proportional hazards regression models were used to estimate the relative risk of CAD during follow-up and cumulative risk during a 10-year interval.

RESULTS

A favorable lifestyle was associated with a 44% (95% confidence interval, 38-48%) lower risk of CAD compared to an unfavorable lifestyle. The relative risk was similarly reduced among subjects subdivided by gender, age group, educational level, and parental history of myocardial infarction. These findings corresponded with a reduced standardized 10-year incidence of CAD of around 40% in each subgroup.

CONCLUSION

In this population-based cohort, a favorable lifestyle was associated with a significant reduction of CAD across strata of non-modifiable risk factors. These findings provide support for lifestyle modification as a means for risk reduction in a range of subgroups within a general healthy population.

Healthy diet and fiber intake are associated with decreased risk of incident symptomatic peripheral artery disease – A prospective cohort study

Peripheral artery disease (PAD) is caused by atherosclerosis and associated with an increased risk of leg amputation, cardiovascular disease, and death. A healthy diet has been shown to reduce the risk of cardiovascular events, but relationships between diet, fiber intake, and incidence of PAD are virtually unknown. The aim was to investigate the long-term impact of diet on the development of PAD among 26,010 middle-aged individuals in the prospective Malmö Diet and Cancer study (MDCS). Data on dietary intake were collected through a 7-day food diary combined with a food questionnaire and a 1-hour interview. Adherence to a recommended intake of six dietary components – saturated fat, polyunsaturated fat, fish and shellfish, fiber, fruit and vegetables, and sucrose – was scored (sum 0–6 points) to assess a diet quality index, adjusting for potential confounders. Cox regression analysis was used to estimate associations between diet variables and PAD incidence expressed in hazard ratios (HR) with 95% CI. During a median follow-up of 21.7 years, 1122 participants developed PAD. Diet score was associated with a reduced risk of PAD in multivariable analysis ( p = 0.03). When mutually adjusting for all dietary variables, only adherence to recommended levels of fiber intake was associated with a reduced risk of incident PAD (HR 0.84; 95% CI 0.72–0.99). In this prospective, population-based study including 26,010 participants with over 20 years of follow-up, a healthy diet, especially a high intake of fiber, was associated with a reduced risk of PAD. Primary prevention programs directed against PAD should therefore include a fiber recommendation.

Intake of fibre and plant foods and the risk of abdominal aortic aneurysm in a large prospective cohort study in Sweden

Purpose

The purpose of this study was to investigate fibre, and plant foods, and its association with AAA risk.

Methods

In this prospective cohort study, Malmö Diet and Cancer Study, baseline data collection was carried out 1991–1996. The study participants’ (n = 26,133) dietary habits were extensively recorded at baseline. The specific diagnosis of AAA in the in-hospital registry was found valid in 95%. The association between plant foods, such as cereals and types of vegetables, and AAA was assessed by using Cox regression analysis expressed as hazard ratios (HR) with 95% confidence intervals (CI).

Results

A high intake of fibre was independently associated with AAA risk (HR per quintile 0.87, 95% CI 0.79–0.97). High intake of vegetables (HR 0.91, 95% CI 0.84–0.98), specifically leaf vegetables (HR 0.87, 95% CI 0.81–0.94), and fruits and berries (HR 0.89, 95% CI 0.82–0.96), citrus (HR 0.91, 95% CI 0.85–0.98) and non-citrus fruits (HR 0.87, 95% CI 0.81–0.95) were independently associated with a decreased AAA risk.

Conclusions

A high intake of fruits and berries and vegetables, in particular leaf vegetables, are associated with a decreased risk of developing AAA.

Electronic supplementary material

The online version of this article (10.1007/s00394-019-02054-w) contains supplementary material, which is available to authorized users.

Lp-PLA2 activity and mass and CRP are associated with incident symptomatic peripheral arterial disease

Long follow up is needed in prospective cohort study evaluation of plasma biomarkers for incident peripheral arterial disease (PAD) Middle-aged PAD-free individuals from the cardiovascular cohort of the Malmö Diet and Cancer study (n = 5550; 1991-94) were followed prospectively for a median time of 23.4 years. The plasma biomarkers lipoprotein-associated phospholipase A2 (Lp-PLA₂) activity and mass, proneurotensin, and CRP, were studied in relation to incidence of PAD until December 31^st, 2016. The diagnosis of PAD could be validated and confirmed in 98%. Cox regression was used to calculate hazard ratios (HR) per 1 standard deviation increment of each respective log transformed plasma biomarker. Cumulative incidence of PAD was 4.4% (men 5.9%, women 3.3%). Adjusting for age, gender, smoking, body mass index, hypertension, diabetes mellitus, Lp-PLA₂ activity (HR 1.33; 95% CI 1.17-1.52), Lp-PLA₂ mass (HR 1.20; 95% CI 1.05-1.37) and CRP (HR 1.55; 95% CI 1.36-1.76) remained independently associated with incident PAD. The plasma biomarkers Lp-PLA₂ activity and mass, and CRP were markers of PAD risk, implying that they might be useful biomarkers for subclinical atherosclerosis and atherosclerotic disease.

A Western dietary pattern is prospectively associated with cardio-metabolic traits and incidence of the metabolic syndrome

The aim of this study was to derive dietary patterns associated with cardio-metabolic traits and to examine whether these predict prospective changes in these traits and incidence of the metabolic syndrome (iMetS). Subjects from the Malmö Diet and Cancer Study cardiovascular cohort without cardio-metabolic disease and related drug treatments at baseline (n 4071; aged 45-67 years, 40 % men) were included. We applied reduced rank regression on thirty-eight foods to derive patterns that explain variation in response variables measured at baseline (waist circumference, TAG, HDL- and LDL-cholesterol, systolic and diastolic blood pressure, fasting glucose and insulin). Patterns were examined in relation to change in cardio-metabolic traits and iMetS in subjects who were re-examined after 16·7 years (n 2704). Two dietary patterns ('Western' and 'Drinker') were retained and explained 3·2 % of the variation in response variables. The 'Western' dietary pattern was inversely associated with HDL-cholesterol and positively with all other response variables (both at baseline and follow-up), but there was no association with LDL at follow-up. After adjustment for potential confounders, the 'Western' dietary pattern was associated with higher risk of iMetS (hazard ratio Q4 v. Q1: 1·47; 95 % CI 1·23, 1·77; P trend=1·5×10-5). The 'Drinker' dietary pattern primarily explained variation in HDL and was not associated with iMetS. In conclusion, this study supports current food-based dietary guidelines suggesting that a 'Western' dietary pattern with high intakes of sugar-sweetened beverages and red and processed meats and low intakes of wine, cheese, vegetables and high-fibre foods is associated with detrimental effects on cardio-metabolic health.

Blood lipid genetic scores, the HMGCR gene and cancer risk: a Mendelian randomization study

Background

It is unclear whether there are causal associations between blood lipids, statin use and cancer risks. Under certain assumptions, Mendelian randomization analysis of a genetic marker for an exposure eliminates reverse causation and confounding.

Methods

We applied Mendelian randomization analysis to genetic scores, comprising 26-41 single-nucleotide polymorphisms (SNPs), as instrumental variables (IVs) for triglycerides and low- and high-density lipoprotein cholesterol (LDLC, HDLC), using a prospective cohort of 26 904 individuals in which there were 6607 incident cancers. We also investigated cancer risk for a SNP (rs12916) in the gene encoding hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR), the targeted enzyme in statin treatment. We used logistic regression and SNP pleiotropy-adjusted analyses to estimate the odds ratio per standard deviation (OR).

Results

The OR for the triglyceride IV as a predictor of any cancer was 0.91 [95% confidence interval (CI): 0.80-1.03] unadjusted, and 0.87 (95% CI: 0.78-0.95) from the pleiotropy-adjusted analysis. For the HMGCR rs12916 per LDLC-lowering T-allele, the OR was 1.09 (95% CI: 1.01-1.18) for prostate cancer and 0.89 (95% CI: 0.82-0.96) for breast cancer. The LDLC IV was not associated with prostate cancer or breast cancer. There were no associations between IVs and cancers of the lung, colon or bladder.

Conclusions

Under the assumptions of Mendelian randomization, there is a causal and negative association between serum triglycerides and risk of any cancer. Further, the HMGCR genetic variant might be associated with risks of prostate and breast cancers but the biological mechanisms behind these findings are unclear, as the LDLC IV was not associated with these cancers.