Phthalates Exposure in Type 2 Diabetic Patients and Diuretic Therapy


In this open clinical trial, 30 subjects with inadequately controlled T2D and eligible, as per good clinical practice, for therapy with SGLT-2 inhibitor, will be randomized to receive a SGLT-2 inhibitor vs other oral-antidiabetic drugs (OADs) therapy for 3 months. Measures will be performed at baseline, after 2 days, after one month and at the end of the study protocol, as per good clinical practice

Full Title of Study: “Exploring the Association Between Phthalates Exposure, Measured Through Their Urinary Metabolites, and Renal Function Impairment in Individuals With TYpe 2 Diabetes – SGLT2 Subprotocol”

Study Type

  • Study Type: Interventional
  • Study Design
    • Allocation: Randomized
    • Intervention Model: Parallel Assignment
    • Primary Purpose: Other
    • Masking: None (Open Label)
  • Study Primary Completion Date: December 30, 2019

Detailed Description

– Total concentrations of MEHP, MEOHP and MEHHP will be quantified, in the laboratories of the Institute of Clinical Physiology, National Research Council, Pisa, in a spot morning urine sample by ultra-HPLC coupled with electrospray ionization/quadrupole time-of-flight mass spectrometry (Agilent UHPLC 1290 infinity coupled to an Agilent 6540 MS-QTOF, Santa Clara, CA) using stable isotope labeled substrates, i.e. MEHP (ring-1,2-13C2, dicarboxyl-13C2), MEHHP, MEHHP 13C4, MEOHP and MEOHP 13C4 that will be purchased from Cambridge Isotope Laboratories (Tewksbury, MA). – Urinary creatinine concentrations will be measured to adjust urinary concentrations of DEHP metabolite (Beckman Coulter AU400, Brea, CA), thus minimizing the influence of urine volume. – Serum and urinary inflammatory markers and adipocytokines will be quantitatively determined using sandwich enzyme-linked immunosorbent assays kits according to the manufacturer's instructions. Optical density will be measured using a microplate reader. – Serum and urinary markers of oxidative stress will be measured by gold standard techniques. In detail, MDA will be quantified by TBARS reactive substances measured by optical density; GSH-Px by a specific assay kit according to the manufacturer's instruction; SOD activity will be determined using a specific SOD kit; urinary 8-isoprostane concentration will be measured by a specific affinity sorbent. (Cayman Chemical, Ann Harbor, MI, USA) according to the manufacturer's instructions. – To analyze mitochondrial DNA we will apply a triplex design previously reported to amplify mitochondria loci located within the MinorArc and MajorArc, respectively. To assess nuclear DNA, we will use RNase P Copy Number Reference. – The phthalates-free diet will be self-administered by the individuals under intervention, following a set of instruction and rules provided by the physicians based on the current literature data.


  • Drug: Dapagliflozin 10 MG
    • SGLT2-inhibitor: Diabetic oral drug with diuretic properties
  • Drug: Hydrochlorothiazide 12.5mg
    • Best known thiazide class diuretic.

Arms, Groups and Cohorts

  • Experimental: Dapaglifozin
    • People undergoing SGLT2i (Dapaglifozin) therapy
  • Experimental: Hydrochlorothiazide
    • People undergoing thiazide (Hydrochlorothiazide) therapy

Clinical Trial Outcome Measures

Primary Measures

  • Urinary Phthalates concentration
    • Time Frame: Changes between baseline and 1 month
    • Exposure to phthalates assessed through urinary concentration of phthalates metabolites spot and 24-hours
  • Urinary Phthalates concentration
    • Time Frame: Changes between baseline and 3 month
    • Exposure to phthalates assessed through urinary excretion spot and 24-hours

Secondary Measures

  • Fasting glucose
    • Time Frame: 1 and 3 months
    • Fasting glucose measured in a fasting morning blood sample
  • Glycated Haemoglobin
    • Time Frame: 1 and 3 months
    • HbA1c in a fasting measured in a morning blood sample
  • Renal function
    • Time Frame: 1 and 3 months
    • Using creatinine measured in a fasting morning blood sample and estimated by eGFR (calculated with the CDK-EPI formula)
  • Macrovascular events
    • Time Frame: 1 and 3 months
    • Number of participants with MACE events (Stroke, Acute Myocardial Infarction, Unstable Angina, Revascularization)
  • Albumin excretion
    • Time Frame: 1 and 3 months
    • Measured by urinary albumin/creatinine ratio

Participating in This Clinical Trial

Inclusion Criteria

  • Individuals of both sex; – Age between 18 and 85 years; – T2D – T2D duration > 6 months – BMI ≤ 40 Kg/m2, – HbA1c > 48 mmol/mol – Eligible for SGLT-2i therapy Exclusion criteria – age >85 years, – eGFR <60 ml/min/1.73 m2, – occurring acute complications

Gender Eligibility: All

Minimum Age: 18 Years

Maximum Age: 85 Years

Are Healthy Volunteers Accepted: No

Investigator Details

  • Lead Sponsor
    • University of Pisa
  • Provider of Information About this Clinical Study
    • Principal Investigator: Anna Solini, Associate Professor – University of Pisa
  • Overall Official(s)
    • Anna Solini, Prof, Principal Investigator, University of Pisa


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Frederiksen H, Nielsen O, Koch HM, Skakkebaek NE, Juul A, Jørgensen N, Andersson AM. Changes in urinary excretion of phthalates, phthalate substitutes, bisphenols and other polychlorinated and phenolic substances in young Danish men; 2009-2017. Int J Hyg Environ Health. 2020 Jan;223(1):93-105. doi: 10.1016/j.ijheh.2019.10.002. Epub 2019 Oct 25.

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