Evaluation of the Thyroid Characteristics and Correlated Factors in Hospitalized Patients with Newly Diagnosed Type 2 Diabetes

Figures & data

Table 1 Demographic and Clinical Characteristics of Subjects

Characteristic	Newly Diagnosed T2DM	Non-T2DM	P
	n = 340	n = 120
Demographic data
Age, years	55.5 (18.0)	55.0 (14.0)	0.532
Male, n (%)	221 (65.0)	74 (61.7)	0.513
Hypertension, n (%)	124 (36.5)	15 (12.5)	< 0.001*
Clinical parameters
BMI, kg/m^2	24.0 (5.1)	24.9 (3.6)	0.756
Systolic BP, mmHg	132 (25)	127 (26)	0.013*
Diastolic BP, mmHg	85 (17)	81 (13)	0.006*
HbA1c, %	12.0 (3.5)	5.7 (0.8)	< 0.001*
FPG, mmol/L	13.2 (7.3)	5.0 (0.9)	< 0.001*
eGFR, mL/min/1.73m^2	90.0 (30.6)	90.2 (22.6)	0.760
Triglyceride, mmol/L	1.66 (1.33)	1.33 (1.24)	0.001*
Total cholesterol, mmol/L	5.03 (1.60)	4.95 (1.19)	0.067
LDL-C, mmol/L	3.28 (1.34)	3.20 (1.06)	0.129
HDL-C, mmol/L	1.00 (0.35)	1.19 (0.38)	< 0.001*
Uric acid, μmol/L	314 (145)	363 (137)	< 0.001*
Thyroid function
FT3, pmol/L	3.54 (0.98)	4.95 (0.84)	< 0.001*
FT4, pmol/L	14.33 (3.47)	16.90 (3.60)	< 0.001*
FT3/FT4 ratio	0.24 (0.08)	0.30 (0.07)	< 0.001*
TSH, μIU/mL	1.31 (1.17)	2.08 (1.63)	< 0.001*
Thyroid dysfunction, n (%)	72 (21.2)	5 (4.2)	< 0.001*

Notes: Continuous data were expressed as mean (standard deviation) or median (interquartile range), categorical data as n (%). *P-value < 0.05.

Abbreviations: T2DM, type 2 diabetes mellitus; BMI, body mass index; BP, blood pressure; HbA1c, glycated hemoglobin; FPG, fasting plasma glucose; eGFR, estimated glomerular filtration rate; LDL-C, low-density lipoprotein cholesterol; HDL-C, high-density lipoprotein-cholesterol; FT3, free triiodothyronine; FT4, free thyroxine; TSH, thyroid stimulating hormone.

Table 2 Distribution of Thyroid Status

Thyroid Status	N (%)	FT3, pmol/L	P1	FT4, pmol/L	P2	TSH, μIU/mL	P3	Positive Thyroid Antibodies	P4
Total	340 (100)	3.54 (0.98)	–	14.44 (3.47)	–	1.31 (1.17)	–	28 (8.5)	–
Euthyroid	268 (78.8)	3.72 (0.78)	–	14.42 (3.23)	–	1.38 (1.09)	–	16 (6.6)	–
Low T3 syndrome	50 (14.7)	2.34 (0.70)	< 0.001*	13.05 (5.02)	0.003*	0.99 (1.05)	< 0.001*	5 (10.4)	0.444
Subclinical hyperthyroidism	14 (4.1)	3.28 (0.78)	0.005*	14.43 (3.38)	0.580	0.30 (0.13)	< 0.001*	4 (30.8)	0.005*
Hypothyroidism	6 (1.8)	2.82 (1.11)	0.001*	10.26 (7.50)	0.061	10.28 (11.53)	< 0.001*	3 (50.0)	0.001*
Subclinical hypothyroidism	2 (0.6)	3.32	0.260	14.77	0.884	5.08	0.018*	0 (0.0)	1.000

Notes: Continuous data were expressed as mean (standard deviation) or median (interquartile range), categorical data as n (%). P, group with thyroid dysfunction versus group in euthyroid status; P₁, comparison of FT3 level; P₂, comparison of FT4 level; P₃, comparison of TSH level; P₄, comparison of proportion of positive thyroid antibodies; *P-value < 0.05.

Abbreviations: FT3, free triiodothyronine; FT4, free thyroxine; TSH, thyroid stimulating hormone.

Table 3 Correlation Between Thyroid Function and Demographic and Metabolic Parameters

Variable	FT3		FT4		FT3/FT4 Ratio		TSH
	Correlation Coefficient	P	Correlation Coefficient	P	Correlation Coefficient	P	Correlation Coefficient	P
Age, years	−0.150	0.006*	−0.148	0.006*	−0.051	0.345	−0.099	0.069
BMI, kg/m^2	0.123	0.029*	0.013	0.817	0.086	0.129	0.133	0.018*
DK or DKA, n (%)	−0.381	< 0.001*	−0.046	0.395	−0.328	< 0.001*	0.016	0.775
Diabetic nephropathy, n (%)	−0.282	< 0.001*	−0.103	0.058	−0.251	< 0.001*	−0.059	0.278
Urinary total protein, mg/24h	−0.334	< 0.001*	−0.050	0.388	−0.327	< 0.001*	−0.046	0.432
Albumin excretion rate, mg/24h	−0.139	0.039*	−0.088	0.193	−0.133	0.048*	−0.073	0.277
eGFR, mL/min/1.73m^2	0.156	0.004*	0.148	0.006*	0.062	0.257	0.045	0.414
Diabetic peripheral neuropathy, n (%)	0.008	0.884	0.150	0.006*	−0.090	0.097	−0.057	0.293
Carotid atherosclerosis, n (%)	−0.130	0.097	−0.217	0.005*	0.022	0.779	−0.045	0.569
HbA1c, %	−0.257	< 0.001*	0.132	0.015*	−0.311	< 0.001*	−0.026	0.632
FPG, mmol/L	0.022	0.691	0.159	0.004*	−0.059	0.281	0.061	0.266
LDL-C, mmol/L	0.077	0.161	−0.012	0.828	0.108	0.047*	−0.094	0.086
HDL-C, mmol/L	0.145	0.007*	0.083	0.129	0.117	0.032*	−0.054	0.326
Triglyceride, mmol/L	0.074	0.173	−0.079	0.145	0.138	0.011*	0.064	0.240
Total cholesterol, mmol/L	0.057	0.292	−0.019	0.726	0.098	0.070	−0.045	0.404
Fasting C-Peptide, μg/L	0.332	< 0.001*	0.031	0.590	0.275	< 0.001*	0.105	0.069
2-h C-Peptide, μg/L	0.434	< 0.001*	0.013	0.821	0.384	< 0.001*	0.123	0.036*
HOMA-IR	0.273	< 0.001*	0.069	0.233	0.205	< 0.001*	0.089	0.123
HOMA-β	0.173	0.003*	0.093	0.109	0.182	0.002*	0.016	0.784
Systolic BP, mm Hg	0.085	0.118	0.060	0.270	0.095	0.082	−0.026	0.629
Diastolic BP, mm Hg	0.170	0.002*	0.093	0.088	0.067	0.217	0.031	0.567

Note: *P-value < 0.05.

Abbreviations: FT3, free triiodothyronine; FT4, free thyroxine; TSH, thyroid stimulating hormone; BMI, body mass index; DK, diabetic ketosis; DKA, diabetic ketoacidosis; eGFR, estimated glomerular filtration rate; HbA1c, glycated hemoglobin; FPG, free plasma glucose; LDL-C, low-density lipoprotein cholesterol; HDL-C, high-density lipoprotein cholesterol; HOMA-IR, homeostasis model assessment of insulin resistance; HOMA-β, homeostasis model assessment of β cell function; BP, blood pressure.

Table 4 Multivariate Analysis of Associated Factors of Diabetic Nephropathy in Patients with Newly Diagnosed T2DM

Variable	OR	β	Wald χ^2	P
Age	1.011	0.011	0.525	0.469
Hypertension	1.212	0.193	0.607	0.607
BMI	1.095	0.092	3.825	0.049*
HOMA-IR	1.021	0.021	7.286	0.007*
HOMA-β	1.001	0.001	1.862	0.172
DK/DKA	2.043	0.715	4.082	0.043*
eGFR	1.000	0.000	0.001	0.980
FT3	0.364	−1.011	11.856	0.001*
FT4	1.102	0.097	2.279	0.131

Note: *P-value < 0.05.

Abbreviations: T2DM, type 2 diabetes mellitus; BMI, body mass index; HOMA-IR, homeostasis model assessment of insulin resistance; HOMA-β, homeostasis model assessment of β cell function; DK, diabetic ketosis; DKA, diabetic ketoacidosis; eGFR, estimated glomerular filtration rate; FT3, free triiodothyronine; FT4, free thyroxine.

Figure 1 Prevalence of DN and levels of urinary total protein in different FT3 quartiles. Quartile 1 (Q1, n = 109), 1.54 to < 3.26 pmol/L; Quartile 2 (Q2, n = 119), 3.26 to < 3.88 pmol/L; Quartile 3 (Q3, n = 112), 3.88 to ≤ 7.18 pmol/L.

Abbreviations: DN, diabetic nephropathy; FT3, free triiodothyronine.