Hubungan kadar Plumbum (Pb) dalam darah dengan fungsi tiroid (TSH-FT4) di daerah perkotaan

SAMSUDIN, Mohamad, dr. Bambang Suryono, Sp.An-KIC.M.Kes

2007 | Tesis | S2 Ilmu Kedokteran Klinis (Epidemiologi Klinik)

Latarbelakang. Akhir-akhir ini banyak dilaporkan adanya kasus Gangguan Akibat Kekurangan Iodium (GAKI) dan perluasan daerah gondok di dataran rendah – termasuk perkotaan– yang cukup kandungan iodium. Pencemaran udara akibat emisi gas buang kendaraan bermotor di perkotaan cukup tinggi (60-70%). Sekitar 70-98% plumbum (Pb) dikeluarkan dari pipa knalpot kendaraan bermotor. Penelitian di Yogyakarta menemukan sebanyak 55,9% subyek terkontaminasi Pb akibat emisi gas buang kendaraan bermotor. Studi lain menemukan ibu–ibu dengan status iodium rendah. Diduga ada faktor lain yang dapat menghambat utilisasi iodium dalam tubuh, sehingga mengakibatkan fungsi tiroid menurun. Wanita usia subur (WUS) merupakan kelompok yang rentan dan sangat berbahaya apabila sering terpapar Pb, hal ini terkait dengan kemungkinan kehamilan yang dapat berakibat buruk bagi janin yang akan dilahirkan. Posisi WUS paling strategis dalam program GAKI, hal ini terkait dengan upaya mencegah hipotiroid kongenital dan kerusakan otak ringan akibat GAKI. Tujuan dan metode. Penelitian ini bertujuan mengetahui hubungan antara kadar Pb dalam darah dengan fungsi tiroid pada WUS risiko terpapar Pb di daerah perkotaan Yogyakarta. Disain penelitian adalah cross-sectional. Lokasi penelitian di daerah padat lalulintas sekitar terminal bus dan perempatan jalan. Subyek penelitian adalah WUS umur 15–49 tahun sebanyak 99 orang. Kadar Pb dalam darah dianalisis dengan metode AAS; kadar TSH dan FT4 dianalisis dengan metode ELISA; kadar Ekskresi Iodium Urine (EIU) dianalisis dengan metode APDM; kadar hemoglobin dianalisis dengan metode CyanmetHb; data konsumsi sianida makanan dan zat gizi diperoleh melalui wawancara dengan menggunakan metode frekuensi makanan semi kuantitatif (Semi-FFQ); dan penentuan status gizi menurut Indeks Massa Tubuh (IMT). Hasil dan kesimpulan. Proporsi WUS menderita hipotiroid sebesar 19,2% (95%CI: 11,4%–26,9%). Proporsi WUS dengan kadar Pb tinggi (PbD ≥50 μg/l) adalah 49,5% (95%CI: 39,6%–59,3%). Hasil uji regresi logistik menunjukkan ada hubungan antara kadar Pb dalam darah dengan fungsi tiroid (p=0,018; RR=3,99; 95%CI: 1,3–12,6). Peran faktor umur kecil sekali (p=0,031; RR=0,92). Hasil uji t menunjukkan tidak ada hubungan antara konsumsi iodium (berdasarkan nilai EIU), protein dan sianida makanan, kadar hemoglobin dan status gizi dengan fungsi tiroid (p>0,05). Kadar Pb tinggi dalam darah merupakan faktor risiko terjadinya hipotiroid pada WUS risiko terpapar Pb di perkotaan.

Background. Recently, there were many reports a occurence of iodine deficiency disorders (IDD) cases and extension of goitre area in lowlands –urban– which had enough resource of iodine. Air pollution that caused by motor–vehicle gas emission has reached high level in urban area (60-70%). The plumbum (Pb) was arround 70- 98% released from pipe of muffler in the motor-vehicle. Research in Yogyakarta found that 55,9% subject was contaminated by plumbum due to gas emission of motor-vehicle. Another research found there were cases of mothers with low iodine status. It is expected that other factors were inhibiting the process of iodine utilization in the body and caused reduction in the thyroid function. The child bearing age women (CBAW) are among vulnerable group when incured by the lead exposure. It is related to posible hazard to their pregnancy and foetus. The CBAW have the strategic position in the IDD program concerning the effort of preventing congenital hypothyroidism and brain damage due to IDD. Objectives and methods. The aim of this study was to measure relationship between blood lead level with thyroid function among CBAW with high risk of Pb exposure in urban area. Study design were cross-sectional. This study conducted in crowded traffic area in Yogyakarta. Subject were 99 CBAW age 15-49 year. Blood lead level was analyzed by AAS method; level of TSH and FT4 was analyzed by ELISA method; level of Urinary Excretion of Iodine (UEI) was analyzed by APDM method; level of haemoglobin was analyzed by CyanmetHb method; data of food cyanide and protein intake were collected by interview using Semi-FFQ; and nutritional status was determined by Body Mass Index (BMI). Results and conclusions. The proportion of CBAW with hypothyroidism was 19,2% (95%CI: 11,4%–26,9%). The CBAW with high blood lead level (bll ≥50 μg/l) was 49,5% (95%CI: 39,6%–59,3%). The logistic regression test result showed there was relationship between blood lead level with thyroid function (p=0,018; RR=3,99; 95%CI: 1,3–12,6). The contribution of age was very small (p=0,031; RR=0,92). The t test result showed there was no relationship between iodine consumption (determined from level of UEI); food cyanide and protein intake; haemoglobin level; and nutrition status with thyroid function (p>0,05). The high blood lead level was the risk factor of hypothyroidism among CBAW with risk of Pb exposure in urban area.

Kata Kunci : Pb Darah,Fungsi Tiroid,Wanita Usia Subur, blood lead, thyroid function, hypothyroidism, child bearing age women