Is kallikrein-8 a blood biomarker for detecting amnestic mild cognitive impairment? Results of the population-based Heinz Nixdorf Recall study

Background Kallikrein-8 (KLK8) might be an early blood-biomarker of Alzheimer’s disease (AD). We examined whether blood KLK8 is elevated in persons with amnestic mild cognitive impairment (aMCI) which is a precursor of AD, compared to cognitively unimpaired (CU) controls. Methods Forty cases and 80 controls, matched by sex and age (± 3years), were participants of the longitudinal population-based Heinz Nixdorf Recall study (baseline: 2000–2003). Standardized cognitive performance was assessed 5 (T1) and 10 years after baseline (T2). Cases were CU at T1 and had incidental aMCI at T2. Controls were CU at T1 and T2. Blood KLK8 was measured at T2. Using multiple logistic regression the association between KLK8 in cases vs. controls was investigated by estimating odds ratios (OR) and 95% confidence intervals (95%CI), adjusted for inter-assay variability and freezing duration. Using receiver operating characteristic (ROC) analysis, the diagnostic accuracy of KLK8 was determined by estimating the area under the curve (AUC) and 95%CI (adjusted for inter-assay variability, freezing duration, age, sex). Results Thirty-seven participants with aMCI vs. 72 CU (36.7%women, 71.0±8.0 (mean±SD) years) had valid KLK8 measurements. Mean KLK8 was higher in cases than in controls (911.6±619.8 pg/ml vs.783.1±633.0 pg/ml). Fully adjusted, a KLK8 increase of 500pg/ml was associated with a 2.68 (1.05–6.84) higher chance of having aMCI compared to being CU. With an AUC of 0.92 (0.86–0.97), blood KLK8 was a strong discriminator for aMCI and CU. Conclusion This is the first population-based study to demonstrate the potential clinical utility of blood KLK8 as a biomarker for incipient AD.

Interaction of Alzheimer’s Disease-Associated Genetic Risk with Indicators of Socioeconomic Position on Mild Cognitive Impairment in the Heinz Nixdorf Recall Study

Background: The apolipoprotein E (APOE) ɛ4 allele is reported to be a strong genetic risk factor for mild cognitive impairment (MCI) and Alzheimer’s disease (AD). Additional genetic loci have been detected that influence the risk for late-onset AD. As socioeconomic position (SEP) is also strongly related to cognitive decline, SEP has been suggested to be a possible modifier of the genetic effect on MCI. Objective: To investigate whether APOE ɛ4 and a genetic sum score of AD-associated risk alleles (GRSAD) interact with SEP indicators to affect MCI in a population-based cohort. Methods: Using data of 3,834 participants of the Heinz Nixdorf Recall Study, APOE ɛ4 and GRSAD by SEP interactions were assessed using logistic regression models, as well as SEP-stratified genetic association analysis. Interaction on additive scale was calculated using the relative excess risk due to interaction (RERI). All analysis were additionally stratified by sex. Results: Indication for interaction on the additive scale was found between APOE ɛ4 and low education on MCI (RERI: 0.52 [95% -confidence interval (CI): 0.01; 1.03]). The strongest genetic effects of the APOE ɛ4 genotype on MCI were observed in groups of low education (Odds ratio (OR): 1.46 [95% -CI: 0.79; 2.63] for≤10 years of education versus OR: 1.00 [95% -CI: 0.43; 2.14] for≥18 years of education). Sex stratified results showed stronger effects in women. No indication for interaction between the GRSAD and SEP indicators on MCI was observed. Conclusion: Results indicate that low education may have an impact on APOE ɛ4 expression on MCI, especially among women.

Population impact of different hypertension management guidelines based on the prospective population-based Heinz Nixdorf Recall study

ObjectiveHypertension guidelines strongly differ between societies. The current American College of Cardiology/American Heart Association (ACC/AHA) guideline recommends higher proportions of the general population for antihypertensive medication than the previous American and European guidelines. How cardiovascular risk differs between persons with and without antihypertensive medication recommendation has not been examined. Additionally, the population impact of American, European and international guidelines has not been compared systematically within the same study population.MethodsWe compared the prevalence of antihypertensive medication recommendation according to the American (Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure 7 (JNC7), ACC/AHA 2017), European (European Society of Hypertension (ESH)/European Society of Cardiology (ESC) 2013/2018), and international (WHO/International Society of Hypertension (ISH) 2003, ISH 2020) guidelines in 3092 participants of the population-based Heinz Nixdorf Recall study not taking antihypertensive medication at the baseline examination (58.1±7.5 years, 48.7% males). We furthermore compared incident cardiovascular events during the 5-year follow-up between participants with and without antihypertensive medication recommendation.ResultsThe ACC/AHA 2017 guideline recommended the highest percentage of participants for antihypertensive medication (45.8%) compared with the JNC7 (37.2%), ESH/ESC 2013 (17.8%), ESC/ESH 2018 (26.7%), WHO/ISH 2003 (20.3%) or ISH 2020 (25.0%) guidelines. Participants with antihypertensive medication recommendation according to the ACC/AHA 2017 guideline had a significantly higher incidence of cardiovascular events during the 5-year follow-up compared with participants without this recommendation (2.5% vs 1.1%, p=0.003).ConclusionsOur results call for randomised controlled trials to investigate whether applying the stricter ACC/AHA 2017 recommendation leads to a reduction in cardiovascular disease.

Prevalence and risk factors of migraine and non-migraine headache in older people – results of the Heinz Nixdorf Recall study

Background The prevalence of migraine and non-migraine headache declines with age. Methods Data from the third visit (2011–2015) of the population-based Heinz Nixdorf Recall study were analysed (n = 2038, 51% women, 65–86 years). Possible risk factors for headache activity (obesity, education, smoking, sports, alcohol, partnership status, living alone, having children, sleep quality, depression, hypertension, diabetes mellitus, stroke, coronary heart disease, medication), and headache symptoms were assessed. We estimated the lifetime prevalence and the prevalence of current active headache of migraine with and without aura, and non-migraine headache. The associations between possible risk factors and headache activity (active vs. inactive) were estimated by age and sex-adjusted odds ratios and 95% confidence intervals (OR [95% CI]) using multiple logistic regression. Results The lifetime prevalence of migraine was 28.6% (n = 584). One hundred and ninety-two (9.4%) had still-active migraine, 168 (3.5%) had migraine with aura, and 416 (5.9%) had migraine without aura. One hundred and sixty-eight (8.2%) had “episodic infrequent migraine, 0–8 headache days/month”, 10 (0.5%) had “episodic frequent migraine, 9–14 headache days/month”, and five (0.2%) had “chronic migraine, ≥15 headache days/month”. Overall, 10 (0.5%) had “chronic headache, any headache on ≥15 days/month”. Female gender and younger age were the most important associated migraine risk factors. Depression (1.62 [1.06; 2.47]) and poor sleep (1.06 [1.00; 1.12]) were associated with migraine and headache activity in general. Antihypertensives were associated with headache remission (0.80 [0.64; 1.00]). Additionally, undertaking less sports (0.72 [0.51; 1.03]) was associated with higher migraine activity. Conclusions Headaches and migraines are not rare in the older population. They are related to mood and sleep disturbance, and migraine even to less physical activity. Antihypertensives are related to headache remission.