Pumarega José, Camargo Judit, Gasull Magda, Olshan Andrew F, Soliman Amr, Chen Yu, Richardson David, Alguacil Juan, Poole Charles, Trasande Leonardo, Porta Miquel
Hospital del Mar Medical Research Institute (IMIM), Barcelona, Spain.
CIBER de Epidemiología y Salud Pública (CIBERESP), Madrid, Spain.
Expo Health. 2022;14(3):581-593. doi: 10.1007/s12403-021-00436-2. Epub 2021 Oct 22.
Trace elements such as cadmium, arsenic, zinc or selenium increase or decrease risk of a wide range of human diseases. Their levels in toenails may provide a measure of mid-term intake of trace elements for studies in humans. However, in biologically and clinically aggressive diseases as pancreatic cancer, the progression of the disease could modify such concentrations and produce reverse causation bias. The aim was to analyze the influence of specific time intervals between several clinical events and the collection of toenails upon concentrations of trace elements in patients with pancreatic cancer. Subjects were 118 incident cases of pancreatic adenocarcinoma prospectively recruited in eastern Spain. Toenails were collected at cancer diagnosis, and soon thereafter interviews were conducted. Information on cancer signs and symptoms was obtained from medical records and patient interviews. Levels of 12 trace elements were determined in toenail samples by inductively coupled plasma mass spectrometry. General linear models adjusting for potential confounders were applied to analyze relations between log concentrations of trace elements and the time intervals, including the interval from first symptom of cancer to toenail collection (iST). Toenail concentrations of the 12 trace elements were weakly or not influenced by the progression of the disease or the diagnostic procedures. Concentrations of aluminum were slightly higher in subjects with a longer iST (age, sex and stage adjusted geometric means: 11.44 vs. 7.75 µg/g for iST > 120 days vs. ≤ 40 days). There was a weak inverse relation of iST with concentrations of zinc and selenium (maximum differences of about 20 and 0.08 µg/g, respectively). Conclusions: concentrations of the trace elements were weakly or not influenced by the development of the disease before toenail collection. Only concentrations of aluminum increased slightly with increasing iST, whereas levels of zinc and selenium decreased weakly. Even in an aggressive disease as pancreatic cancer, toenail concentrations of trace elements may provide a valid measure of mid-term intake of trace elements, unaffected by clinical events and disease progression.
The online version contains supplementary material available at 10.1007/s12403-021-00436-2.
镉、砷、锌或硒等微量元素会增加或降低多种人类疾病的风险。它们在脚趾甲中的含量可为人体研究中微量元素的中期摄入量提供一种衡量指标。然而，在胰腺癌等具有生物学和临床侵袭性的疾病中，疾病的进展可能会改变这些浓度，并产生反向因果偏差。目的是分析胰腺癌患者在几个临床事件与脚趾甲采集之间的特定时间间隔对微量元素浓度的影响。研究对象为西班牙东部前瞻性招募的118例胰腺腺癌新发病例。在癌症诊断时采集脚趾甲，随后不久进行访谈。从病历和患者访谈中获取有关癌症体征和症状的信息。通过电感耦合等离子体质谱法测定脚趾甲样本中12种微量元素的含量。应用调整潜在混杂因素的一般线性模型来分析微量元素对数浓度与时间间隔之间的关系，包括从癌症首发症状到脚趾甲采集的间隔时间（iST）。12种微量元素的脚趾甲浓度受疾病进展或诊断程序的影响较弱或无影响。iST较长的受试者中铝的浓度略高（年龄、性别和分期调整后的几何均值：iST＞120天与≤40天相比，分别为11.44与7.75μg/g）。iST与锌和硒的浓度呈弱负相关（最大差异分别约为20和0.08μg/g）。结论：在采集脚趾甲之前，微量元素浓度受疾病发展的影响较弱或无影响。只有铝的浓度随iST增加而略有升高，而锌和硒的水平则略有下降。即使在胰腺癌这种侵袭性疾病中，脚趾甲中的微量元素浓度也可能为微量元素的中期摄入量提供一个有效的衡量指标，不受临床事件和疾病进展的影响。
在线版本包含可在10.1007/s12403-021-00436-2获取的补充材料。
