You will be provided with a reference and some statements. Please determine whether each statement is 'supported', 'unsupported', or 'unknown' with respect to the reference. Please note:
First, assess whether the reference contains any valid content. If the reference contains no valid information, such as a 'page not found' message, then all statements should be considered 'unknown'.
If the reference is valid, for a given statement: if the facts or data it contains can be found entirely or partially within the reference, it is considered 'supported' (data accepts rounding); if all facts and data in the statement cannot be found in the reference, it is considered 'unsupported'.

You should return the result in a JSON list format, where each item in the list contains the statement's index and the judgment result, for example:
[
    {
        "idx": 1,
        "result": "supported"
    },
    {
        "idx": 2,
        "result": "unsupported"
    }
]

Below are the reference and statements:
<reference>
1. Nutr Metab Cardiovasc Dis. 2022 Aug;32(8):1924-1935. doi: 
10.1016/j.numecd.2022.05.005. Epub 2022 May 20.

Serum copper-to-zinc ratio is associated with heart failure and improves risk 
prediction in middle-aged and older Caucasian men: A prospective study.

Kunutsor SK(1), Voutilainen A(2), Kurl S(2), Laukkanen JA(3).

Author information:
(1)National Institute for Health Research Bristol Biomedical Research Centre, 
University Hospitals Bristol and Weston NHS Foundation Trust and the University 
of Bristol, Bristol, UK; Musculoskeletal Research Unit, Translational Health 
Sciences, Bristol Medical School, University of Bristol, Learning & Research 
Building (Level 1), Southmead Hospital, Bristol, UK; Central Finland Health Care 
District Hospital District, Department of Medicine, Finland District, Jyväskylä, 
Finland; Diabetes Research Centre, University of Leicester, Leicester General 
Hospital, Gwendolen Road, Leicester, LE5 4WP, UK. Electronic address: 
setor.kunutsor@bristol.ac.uk.
(2)Institute of Public Health and Clinical Nutrition, University of Eastern 
Finland, Kuopio, Finland.
(3)Central Finland Health Care District Hospital District, Department of 
Medicine, Finland District, Jyväskylä, Finland; Institute of Public Health and 
Clinical Nutrition, University of Eastern Finland, Kuopio, Finland; Institute of 
Clinical Medicine, Department of Medicine, University of Eastern Finland, 
Kuopio, Finland.

BACKGROUND AND AIMS: Serum copper (Cu) and zinc (Zn) may play a role in the 
development of adverse cardiovascular outcomes including heart failure (HF). 
Serum Cu/Zn-ratio has been shown to be a risk indicator for cardiovascular 
disease, but its relationship with HF has not been previously investigated. We 
aimed to assess the association between Cu/Zn-ratio and incident HF risk using a 
prospective cohort study.
METHODS AND RESULTS: Study participants were recruited in eastern Finland with 
baseline examinations carried out between March 1998 and December 2001. Serum 
levels of Cu and Zn were measured using atomic absorption spectrometry in 1866 
men aged 42-61 years without a history of HF at baseline. Multivariable-adjusted 
hazard ratios (HRs) with confidence intervals (CIs) were calculated for incident 
HF. During 26.5 years median follow-up, 365 HF cases occurred. Restricted cubic 
splines suggested linear relationships of serum Cu/Zn-ratio, Cu and Zn with HF 
risk. A unit increase in Cu/Zn-ratio was associated with an increased HF risk in 
analysis adjusted for several potential confounders including nutritional 
factors such as total energy intake, intake of fruits, berries and vegetables, 
and red meat (HR 1.63; 95% CI 1.06-2.51). The corresponding 
multivariable-adjusted HRs (95% CIs) for serum Cu and Zn were 2.42 (1.32-4.44) 
and 1.34 (0.50-3.63), respectively. Addition of Cu/Zn-ratio to a HF risk 
prediction model was associated with improved risk prediction.
CONCLUSION: In middle-aged and older Finnish men, increased serum Cu/Zn-ratio is 
associated with an increased risk of HF in a linear dose-response fashion and 
might improve HF risk assessment.

Copyright © 2022 The Italian Diabetes Society, the Italian Society for the Study 
of Atherosclerosis, the Italian Society of Human Nutrition and the Department of 
Clinical Medicine and Surgery, Federico II University. Published by Elsevier 
B.V. All rights reserved.

DOI: 10.1016/j.numecd.2022.05.005
PMID: 35680488 [Indexed for MEDLINE]

Conflict of interest statement: Declaration of competing interest None.
</reference>

<statements>
1. Copper and zinc associations were observational rather than proven therapeutic targets
2. In a prospective cohort of 1,866 Finnish men aged 42–61 years followed for a median of 26.5 years, 365 heart failure cases occurred
3. A unit increase in serum copper-to-zinc ratio was associated with heart failure risk after adjustment for nutritional and other confounders (hazard ratio 1.63, 95% CI 1.06–2.51)
4. Serum copper alone was associated with heart failure risk (hazard ratio 2.42, 95% CI 1.32–4.44), whereas serum zinc alone was not statistically significant (hazard ratio 1.34, 95% CI 0.50–3.63)
5. Addition of the copper-to-zinc ratio improved heart failure risk prediction
6. Copper and zinc are associated with cardiovascular risk in prospective cohorts, but no interventional outcome evidence is supplied
</statements>

Begin the assessment now. Output only the JSON list, without any conversational text or explanations.