Dietary Iron Intake and Incident Type 2 Diabetes in Chinese Middle-Aged and Elderly Population: A Prospective Cohort Study

Abstract Objectives Excessive dietary iron intake may lead to iron overload and further induce pancreatic islet damage to increase risk of diabetes, which has a higher prevalence in middle-aged and elderly population. We aimed to explore the association between dietary iron intake and incident type 2 diabetes (T2D) in Chinese middle-aged and elderly population. Methods This study was based on the Guangzhou Nutrition and Health Study (GNHS), an on-going, community-based prospective cohort study that recruited participants aged 40–75 years from 2008. All participants were followed up every three years. 2765 participants free of diabetes were included in data analysis. Dietary iron intake was obtained by a validated food-frequency questionnaire at baseline. T2D was ascertained by self-reported diabetes medications, fasting glucose ≥7.0 mmol/L or glycosylated hemoglobin ≥6.5%. Cox proportional hazards models were used to estimate HRs and 95% CIs. Results We ascertained 209 incident diabetes cases during 13,634 person-years of observation. The mean ± SD intakes of dietary total iron, heme iron and nonheme iron among all participants were 20.40 ± 2.73 mg/d, 1.26 ± 0.62 mg/d and 19.14 ± 2.66 mg/d, respectively. The multivariate-adjusted HR and 95% CI for T2D for the highest quartile of heme iron intake compared with the lowest quartile was 2.11 (95% CI: 1.14–3.89, P-trend = 0.014). However, the association between total iron intake or a nonheme iron intake with T2D risk was no significant difference. The adjusted HR for T2D risk was 1.79 (95% CI:1.05–3.08, P-trend = 0.037) for heme iron intake from red meat, while no association was found for heme iron intake from poultry or fish. Conclusions Greater intake of heme iron, especially heme iron from red meat, was associated with higher risk of incident T2D in Chinese middle-aged and elderly population, while intakes of total iron and nonheme were not related to diabetes. Controlling heme iron intake, especially red meat intake, may be a target to prevent T2D in middle-aged and elderly population. Funding Sources The National Science Foundation of China; the National Science Foundation of Guangdong Province, China.

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Dietary iron intake and the risk of type 2 diabetes mellitus in middle-aged and older adults in urban China: A Prospective Cohort Study

British Journal Of Nutrition ◽

10.1017/s0007114520005048 ◽

2020 ◽

pp. 1-22

Author(s):

Shu-Yi Li ◽

Fan Wang ◽

Xiao-Ting Lu ◽

Rong-Huan Zhong ◽

Jing-An Long ◽

...

Keyword(s):

Diabetes Mellitus ◽

Older Adults ◽

Heme Iron ◽

Nonheme Iron ◽

Total Iron ◽

Urban China ◽

Dietary Iron ◽

Iron Intake ◽

Middle Aged

Abstract The association between dietary iron intake and diabetes risk remains inconsistent. We aimed to explore the association of dietary iron intake and type 2 diabetes mellitus (T2DM) risk in middle-aged and older adults in urban China. This study used data from the Guangzhou Nutrition and Health Study (GNHS), an on-going community-based prospective cohort study. Participants were recruited from 2008 to 2013 in Guangzhou community. 2,696 participants aged 40-75 years without T2DM at baseline were included in data analyses, with a median of 5.6 (IQR: 4.1-5.9) years of follow-up. T2DM was identified by self-reported diagnosis, fasting glucose ≥7.0 mmol/L, or glycosylated hemoglobin ≥6.5%. Cox proportional hazard models were used to estimate HRs and 95%CIs. We ascertained 205 incident T2DM cases during 13,476 person-years. The adjusted HR for T2DM risk in the fourth quartile of heme iron intake was 1.92 (95%CI: 1.07, 3.46; P-trend=0.010), compared with the first quartile intake. These significant associations were found in heme iron intake from total meat (HR:2.74; 95%CI: 1.22, 6.15; P-trend=0.011) and heme iron intake from red meat (HR:1.86; 95%CI: 1.01, 3.44; P-trend=0.034), but not heme iron intake from processed meat, poultry or fish/shellfish. The association between dietary intake of total iron or nonheme iron with T2DM risk had no significance. Our findings suggested that higher dietary intake of heme iron (especially from red meat), but not total iron or nonheme iron, was associated with greater T2DM risk in middle-aged and older adults.

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Association between Living Alone and Incident Type 2 Diabetes Among Middle-Aged Individuals in South Korea: A Nationwide Cohort Study

SSRN Electronic Journal ◽

10.2139/ssrn.3460683 ◽

2019 ◽

Author(s):

Ga Eun Nam ◽

Wonsock Kim ◽

Kyungdo Han ◽

Jin-Hyung Jung ◽

Byoungduck Han ◽

...

Keyword(s):

Type 2 Diabetes ◽

Cohort Study ◽

South Korea ◽

Living Alone ◽

Middle Aged ◽

Incident Type ◽

Incident Type 2 Diabetes

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Total and Nonheme Dietary Iron Intake Is Associated with Metabolic Syndrome and Its Components in Chinese Men and Women

Nutrients ◽

10.3390/nu10111663 ◽

2018 ◽

Vol 10 (11) ◽

pp. 1663 ◽

Cited By ~ 15

Author(s):

Zhenni Zhu ◽

Fan Wu ◽

Ye Lu ◽

Chunfeng Wu ◽

Zhengyuan Wang ◽

...

Keyword(s):

Metabolic Syndrome ◽

Serum Ferritin ◽

Smoking Status ◽

Heme Iron ◽

Nonheme Iron ◽

Total Iron ◽

Positive Trend ◽

Dietary Iron ◽

Iron Intake ◽

Men And Women

The causal relationship between serum ferritin and metabolic syndrome (MetS) remains inconclusive. Dietary iron intake increases serum ferritin. The objective of this study was to evaluate associations of total, heme, and nonheme dietary iron intake with MetS and its components in men and women in metropolitan China. Data from 3099 participants in the Shanghai Diet and Health Survey (SDHS) obtained during 2012–2013 were included in this analysis. Dietary intake was assessed by 24-h diet records from 3 consecutive days. Multivariate generalized linear mixed models were used to evaluate the associations of dietary iron intake with MetS and its components. After adjustment for potential confounders as age, sex, income, physical exercise, smoking status, alcohol use, and energy intake, a positive trend was observed across quartiles of total iron intake and risk of MetS (p for trend = 0.022). Compared with the lowest quartile of total iron intake (<12.72 mg/day), the highest quartile (≥21.88 mg/day) had an odds ratio (95% confidence interval), OR (95% CI), of 1.59 (1.15,2.20). In addition, the highest quartile of nonheme iron intake (≥20.10 mg/day) had a 1.44-fold higher risk of MetS compared with the lowest quartile (<11.62 mg/day), and higher risks of MetS components were associated with the third quartiles of total and nonheme iron intake. There was no association between heme iron intake and risk of MetS (p for trend = 0.895). Associations for total and nonheme iron intake with MetS risk were found in men but not in women. Total and nonheme dietary iron intake was found to be positively associated with MetS and its components in the adult population in metropolitan China. This research also revealed a gender difference in the association between dietary iron intake and MetS.

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