Protein Intake Among Patients with Insulin-Treated Diabetes is Linked to Poor Glycemic Control: Findings of NHANES Data

Figures & data

Figure 1 Flow-chart of study design.

Table 1 Sample Characteristics by Quartiles of Protein Intake (N = 990)

	Q1	Q2	Q3	Q4	p-value
	N = 248	N = 247	N = 248	N = 247
Handgrip strength (Kg)	54.8 (17.9)	62.2 (21.3)	64.6 (18.3)	73.8 (21.6)	<0.001
Age (years)	64.6 (10.5)	63.7 (10.9)	62.5 (11.2)	59.5 (11.0)	<0.001
Gender					<0.001
Men	75 (30.2%)	116 (47.0%)	131 (52.8%)	188 (76.1%)
Women	173 (69.8%)	131 (53.0%)	117 (47.2%)	59 (23.9%)
Race					0.47
NH White	84 (33.9%)	89 (36.0%)	101 (40.7%)	89 (36.0%)
NH Black	86 (34.7%)	76 (30.8%)	61 (24.6%)	73 (29.6%)
Mex American	30 (12.1%)	32 (13.0%)	32 (12.9%)	40 (16.2%)
Other race/ethn	48 (19.4%)	50 (20.2%)	54 (21.8%)	45 (18.2%)
Education					0.10
<11 grade	92 (37.2%)	84 (34.1%)	71 (28.6%)	63 (25.5%)
HS displ or GED	57 (23.1%)	51 (20.7%)	64 (25.8%)	60 (24.3%)
Some College	68 (27.5%)	70 (28.5%)	71 (28.6%)	71 (28.7%)
>college	30 (12.1%)	41 (16.7%)	42 (16.9%)	53 (21.5%)
Smoking					0.26
Never	135 (54.4%)	122 (49.4%)	122 (49.2%)	108 (43.7%)
Former	74 (29.8%)	85 (34.4%)	93 (37.5%)	96 (38.9%)
Current smoker	39 (15.7%)	40 (16.2%)	33 (13.3%)	43 (17.4%)
Alcohol drinking					<0.001
No	80 (32.3%)	67 (27.1%)	84 (33.9%)	67 (27.1%)
Yes	101 (40.7%)	128 (51.8%)	127 (51.2%)	142 (57.5%)
Missing	67 (27.0%)	52 (21.1%)	37 (14.9%)	38 (15.4%)
BMI (kg/m2)	32.2 (7.2)	31.9 (7.1)	32.8 (7.4)	32.3 (7.3)	0.59
BMI categories					0.76
Underweight	2 (0.8%)	0 (0.0%)	1 (0.4%)	0 (0.0%)
Normal	29 (11.7%)	36 (14.6%)	33 (13.3%)	30 (12.1%)
Overweight	72 (29.0%)	70 (28.3%)	70 (28.2%)	80 (32.4%)
Obese	145 (58.5%)	141 (57.1%)	144 (58.1%)	137 (55.5%)
Sedentary activity					0.74
≤3 hrs	50 (20.2%)	50 (20.2%)	38 (15.3%)	44 (17.8%)
3–6 hrs	79 (31.9%)	79 (32.0%)	79 (31.9%)	74 (30.0%)
6+ hrs	119 (48.0%)	118 (47.8%)	131 (52.8%)	129 (52.2%)
Income to poverty ratio					0.056
<1.30	104 (46.0%)	84 (36.5%)	85 (36.2%)	76 (32.6%)
1.3–3.5	84 (37.2%)	88 (38.3%)	95 (40.4%)	94 (40.3%)
>3.5	38 (16.8%)	58 (25.2%)	55 (23.4%)	63 (27.0%)
HbA1c (%)	7.2 (1.8)	7.4 (1.8)	7.5 (1.9)	7.6 (1.7)	0.20
Poor glycemic control	112 (45.2%)	115 (46.6%)	116 (46.8%)	137 (55.5%)	0.087
Diabetes duration (years)	13.1 (10.3)	12.2 (10.7)	10.9 (9.7)	10.7 (10.4)	0.032
Hypertension	179 (74.6%)	176 (72.7%)	175 (71.7%)	169 (69.0%)	0.58
CVD	97 (39.1%)	73 (29.6%)	66 (26.6%)	46 (18.6%)	<0.001
Use insulin	65 (26.2%)	72 (29.1%)	64 (25.8%)	73 (29.6%)	0.70
Taking diabetic pills	183 (73.8%)	177 (71.7%)	174 (70.2%)	178 (72.7%)	0.83

Table 2 Odds Ratio (95% CI) for Poor Glycemic Control by Quartiles of Protein Intake

	Quartiles of Protein Intake							P for Trend
	Q1	Q2		Q3		Q4
Model 1	1.00	1.37	(0.79–2.38)	1.33	(0.71–2.49)	2.32	(1.20–4.50)	0.033
Model 2	1.00	1.68	(0.93–3.04)	1.62	(0.78–3.38)	2.62	(1.29–5.33)	0.025
Model 3	1.00	1.35	(0.72–2.51)	1.44	(0.63–3.32)	1.70	(0.73–3.94)	0.251
Model 4	1.00	1.59	(0.86–2.95)	1.68	(0.75–3.76)	2.55	(1.02–6.39)	0.073

Notes: Model 1 adjusted for age, gender, race and energy intake. Model 2 further adjusted for sedentary activity, income, education, smoking, BMI (continuous), handgrip strength (quartiles). Model 3 further adjusted for insulin use, medication for diabetes, and duration of diabetes. Model 4 excluded those with CKD.

Figure 2 Interaction between insulin use and protein intake in relation to poor glycemic control.

Notes: Model adjusted for age, gender, race, energy intake, muscle strength, sedentary activity, income-to-poverty ratio, education, smoking, alcohol drinking, BMI, other medications for diabetes, and duration of diabetes.