TY - JOUR

T1 - Diethylhexyl phthalates is associated with insulin resistance via oxidative stress in the elderly

T2 - a panel study

AU - Kim, Jin Hee

AU - Park, Hye Yin

AU - Bae, Sanghyuk

AU - Lim, Youn-Hee

AU - Hong, Yun-Chul

PY - 2013

Y1 - 2013

N2 - BACKGROUND: Insulin resistance (IR) is believed to be the underlying mechanism of metabolic syndrome and type 2 diabetes mellitus (DM). Recently, a few studies have demonstrated that phthalates could cause oxidative stress which would contribute to the development of IR. Therefore, we evaluated whether exposure to phthalates affects IR, and oxidative stress is involved in the phthalates-IR pathway.METHODS: We recruited 560 elderly participants, and obtained blood and urine samples during repeated medical examinations. For the determination of phthalate exposure, we measured urinary levels of mono-(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP) and mono-(2-ethyl-5-oxohexyl) phthalate (MEOHP) as metabolites of diethylhexyl phthalates (DEHP), and mono-n-butyl phthalate (MnBP) as a metabolite of di-butyl phthalate (DBP). Malondialdehyde (MDA), an oxidative stress biomarker, was also measured in urine samples. We measured serum levels of fasting glucose and insulin, and derived the homeostatic model assessment (HOMA) index to assess IR. A mixed-effect model and penalized regression spline were used to estimate the associations among phthalate metabolites, MDA, and IR.RESULTS: The molar sum of MEHHP and MEOHP (∑DEHP) were significantly associated with HOMA (β = 0.26, P = 0.040), and the association was apparent among participants with a history of DM (β = 0.88, P = 0.037) and among females (β = 0.30, P = 0.022). However, the relation between MnBP and HOMA was not found. When we evaluated whether oxidative stress is involved in increases of HOMA by ∑DEHP, MDA levels were significantly associated with increases of ∑DEHP (β = 0.11, P<0.001) and HOMA (β = 0.49, P = 0.049).CONCLUSIONS: Our study results suggest that exposure to DEHP in the elderly population increases IR, which is related with oxidative stress, and that participants with a history of DM and females are more susceptible to DEHP exposure.

AB - BACKGROUND: Insulin resistance (IR) is believed to be the underlying mechanism of metabolic syndrome and type 2 diabetes mellitus (DM). Recently, a few studies have demonstrated that phthalates could cause oxidative stress which would contribute to the development of IR. Therefore, we evaluated whether exposure to phthalates affects IR, and oxidative stress is involved in the phthalates-IR pathway.METHODS: We recruited 560 elderly participants, and obtained blood and urine samples during repeated medical examinations. For the determination of phthalate exposure, we measured urinary levels of mono-(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP) and mono-(2-ethyl-5-oxohexyl) phthalate (MEOHP) as metabolites of diethylhexyl phthalates (DEHP), and mono-n-butyl phthalate (MnBP) as a metabolite of di-butyl phthalate (DBP). Malondialdehyde (MDA), an oxidative stress biomarker, was also measured in urine samples. We measured serum levels of fasting glucose and insulin, and derived the homeostatic model assessment (HOMA) index to assess IR. A mixed-effect model and penalized regression spline were used to estimate the associations among phthalate metabolites, MDA, and IR.RESULTS: The molar sum of MEHHP and MEOHP (∑DEHP) were significantly associated with HOMA (β = 0.26, P = 0.040), and the association was apparent among participants with a history of DM (β = 0.88, P = 0.037) and among females (β = 0.30, P = 0.022). However, the relation between MnBP and HOMA was not found. When we evaluated whether oxidative stress is involved in increases of HOMA by ∑DEHP, MDA levels were significantly associated with increases of ∑DEHP (β = 0.11, P<0.001) and HOMA (β = 0.49, P = 0.049).CONCLUSIONS: Our study results suggest that exposure to DEHP in the elderly population increases IR, which is related with oxidative stress, and that participants with a history of DM and females are more susceptible to DEHP exposure.

KW - Aged

KW - Aged, 80 and over

KW - Aging

KW - Blood Glucose/metabolism

KW - Dibutyl Phthalate/metabolism

KW - Diethylhexyl Phthalate/metabolism

KW - Environmental Pollutants/metabolism

KW - Fasting

KW - Female

KW - Humans

KW - Insulin/blood

KW - Insulin Resistance

KW - Male

KW - Malondialdehyde/urine

KW - Middle Aged

KW - Oxidative Stress

KW - Phthalic Acids/metabolism

KW - Regression Analysis

KW - Sex Factors

U2 - 10.1371/journal.pone.0071392

DO - 10.1371/journal.pone.0071392

M3 - Journal article

C2 - 23977034

VL - 8

JO - PLoS ONE

JF - PLoS ONE

SN - 1932-6203

IS - 8

M1 - e71392

ER -