- Click here for explanation of classification scheme.

The purpose of the research was to investigate the relationships between serum uric acid, the plasma response to an oral glucose load, and plasma lipoprotein levels in subjects with chronic spinal cord injury.

• Male
• Chronic spinal cord injury
• Normal liver function
• Normal renal function
• No prior history diabetes
• No prior history gout

• Not specifically mentioned; but by inference:
  • Abnormal liver function
  • Abnormal renal function
  • Prior history diabetes
  • Prior history gout

Recruitment

• All subjects were studied during their annual physical exams at a veterans medical center 

Design

• After an overnight fast, blood samples were collected for:
  • Serum uric acid
  • Serum total cholesterol
  • Triglycerides
  • High density lipoprotein cholesterol
• After overnight fasting, an oral glucose tolerance test was performed:
  • 75 grams glucose
  • Blood was drawn at -5, 0, 30, 60, 90, 120, and 180 minutes
  • Plasma glucose and plasma insulin were measured

Statistical Analysis:

• All results expressed as mean + SEM
• Unpaired Student's t-test was used to assess the significance of differences between mean serum uric acid level in subjects with and without hyperinsulinemia
• Unpaired Student's t-test was used to assess the significance of differences between serum lipoprotein levels in subjects with and without hyperinsulinemia
• ANOVA was used to determine the significance of differences in serum uric acid, serum lipoprotein, peak plasma insulin, and peak plasma glucose levels among the groups
• Linear regression analysis was used to assess potential correlations among serum uric acid and insulin response to oral glucose load, age, BMI, and lipoprotein levels
• Linear regression analysis was used to assess potential correlations between BMI and the percent body weight consisting of fat 

Timing of Measurements:

• Measurements were collected after an overnight fast
• Plasma glucose and insulin concentrations were measured at -5, 0, 30, 60, 90, 120, and 180 minutes during an oral glucose tolerance test

 

Dependent Variables

• Serum uric acid
  • Measured by SMAC (Hitachi: 747-100, Japan)
• Serum total cholesterol
  • Measured by SMAC (Hitachi: 747-100, Japan)
• Serum triglycerides
  • Measured by SMAC (Hitachi: 747-100, Japan)
  • Hypertriglyceridemia was defined as serum triglyceride > 175 mg/dl
• Serum high density lipoprotein
  • Measured by the dextran sulfate method (Technicon HDL Cholesterol precipitation reagent, Technicon Instruments Corporation, Tarrytown, NY)
• Serum low density lipoprotein
  • Calculated from the equation:  LDL-chol = (TC-HDL) - (TG/5)
• Oral glucose tolerance as determined by sequential measurement of plasma glucose and plasma insulin
  • Plasma glucose measured by STAT 2300 (Yellow Springs Instrument Corporation, Yellow Springs, OH)
  • Plasma insulin measured by radioimmunoassay
  • Criteria for determination of normal glucose tolerance, impaired glucose tolerance, or diabetes were those of the 1979 National Diabetes Data Group
  • Hyperinsulinemia was defined as peak plasma insulin > 150µ/ml during the oral glucose tolerance test

  Independent Variables

• Male
• Chronic spinal cord injury 

 

Initial N:

• N = 197 (100% males)
  • 103 paraplegic (52%)
  • 94 quadriplegic (48%)

 

Attrition (final N):

• N/A

 

Age:

• Mean age 50 + 1 years (21-77)

 

Ethnicity:

• Not mentioned

 

Other relevant demographics:

• Mean date of injury 18 + 1 years (1-49)

 

Anthropometrics:

• Mean BMI 25 + 0.4 kg/m² (15.8-47.8 kg/m²)
  • BMI was classified as normal (< 27.8 kg/m²) or obese (> 27.8 kg/m²)

 

Location:

• Veterans Affairs Medical Center, Bronx, NY

 

 

Concentrations of serum uric acid, carbohydrate, and lipid metabolic parameters in the study groups:

Variables	SCI (N = 197)	Paraplegic (N = 103)	Quadriplegic (N = 94)
Uric Acid (mg/dl)	5.6±0.1	5.4±0.2	5.8±0.2
Total Cholesterol (mg/dl)	188±3	191±4	185±4
Triglycerides (mg/dl)	122± 6	130± 9	114± 8
High Density Lipoprotein (mg/dl)	39± 1	38± 1	39±1
Low Density Lipoprotein (mg/dl)	124 ±3	125 ±3	123±4
Oral Glucose Peak (mg/dl)	186 ±4	184±6	188 ±5
Serum Insulin Peak (uU/ml)	159 ±10	143 ±13	175±14

 

Concentrations of serum uric acid, carbohydrate, and lipid metabolic parameters in subjects with normal glucose tolerance, impaired glucose tolerance, and diabetes:

Variables	Normal Glucose Tolerance (N = 103)	Impaired Glucose Tolerance (N = 58)	Diabetes (N = 36)
Uric Acid (mg/dl)	5.6±0.2	5.6±0.2	5.7±0.3
Total Cholesterol (mg/dl)	184±4	197±6	186±6
Triglycerides (mg/dl)	116±8	116 ±8	152±19
High Density Lipoprotein (mg/dl)	38 ±1	40±2	38±2
Low Density Lipoprotein (mg/dl)	123±3	129±5	121 ±6
Oral Glucose Peak (mg/dl)	155 ±3	190 ±3	267±8
Serum Insulin Peak (uU/ml)	143±12	188±19	155±24

 

The authors concluded that hyperuricemia is associated with hyperinsulinemia, obesity, and abnormal lipoprotein parameters in persons with chronic SCI, as in the able-bodied population.  The authors stated that the cluster of symptoms delineated is more prevalent in spinal cord injured persons than in the general population.

• Study included only males
• Co-existing morbidities other than hepatic, renal, obesity, and diabetes are not described
• Ethnicity of subjects is not described