                      ! ! "#$% &  ’ $(   )* +,-   - "++..   - $(/   / 0 # ,  / 0 .  & / 0 #   0   + 0  1  %(#  Magnesium is a major determinant of insulin and glucose metabolism. The lower the magnesium, the greater the amount of insulin required to metabolise the same amount of glucose load, indicating insulin insensitivity. Many studies have reported hypomagnesaemia in diabetes mellitus and its relation to poor glycaemic control. This study provides overview regarding the level of serum mag nesium among patients with type 2 diabetes mellitus in the Hospital University Science Malaysia (HUSM) and correlates the level with diabetic control as measured by Hb A1c .    A comparative cross sectional study was conducted among 75 good control (Hb A1c ≤ 7.0% in two con secutive reading or one ≤6.5%) and 75 poor glycaemic control (two Hb A1c > 7.0% readings or one ≥6.5% reading over the study period) who attended the OutPatient Department Clinic and Medical Specialist Clinic HUSM, Kelantan. The patient had been called for sampling of serum magnesium level within three weeks of last the Hb A1c result. ( The proportion of hypomagnesaemia was 8.6% and seen mostly among the poor glycaemic control group. The mean serum magnesium level in good glycaemic control patients (0.94 ± 0.10 mmol/L) was significantly higher than the poor glycaemic con trol group (0.88 ± 0.10 mmol/L, <0.05). Significant but weak inverse correlation were observed be tween serum magnesium levels and Hb A1c in both groups (r=0.22 and =0.004 in poor control group, r= 0.26 and =0.020 in good control group). # Subjects with poor glycaemic control had significantly lower magnesium level than good glycaemic control. There was significant correlation be tween serum magnesium level and glycaemic control. 1 2      ($/+#$ Type 2 diabetes has been associated with hypomagnesaemia compared to nondiabetic subjects. 1 Hypomagnesaemia may be a con   # : T Salwani T Ismail, Jabatan Patologi Kimia, Pusat Pengajian Sains Perubatan, Kampus Kesihatan USM, 16150 Kubang Kerian, Kelantan E mail: tusti@usm.my         sequence of insulin resistance and may wors en insulin resistance, a condition that often precedes the development of frank diabetes, 2 and may alter the entry of glucose into cells. 3 Possible causes of hypomagnesaemia in diabetes mellitus include poor oral magne sium intake, renal magnesium loss, poor gas